colorimetricdetectionofammoniausingsynthesizedsilver...

Research ArticleColorimetric Detection of Ammonia Using Synthesized SilverNanoparticles from Durian Fruit Shell

Eman Alzahrani

Department of Chemistry College of Science Taif University PO Box 11099 Taif 21944 Saudi Arabia

Correspondence should be addressed to Eman Alzahrani em-s-zhotmailcom

Received 10 August 2020 Revised 21 September 2020 Accepted 22 September 2020 Published 20 October 2020

Academic Editor Patricia E Allegretti

Copyright copy 2020 Eman Alzahrani $is is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

$ere has been increased interest in the production of nanoparticles (NP) through green chemistry $is article used durian fruitshell aqueous solution that acts as a reductive preparation of silver NPs $e silver nanoparticles have a size of approximately25 nm $e NP size uniformity was determined by the SEM and TEM analysis X-ray diffraction technique was used tocharacterize crystalline silver nanoparticles face-centered cubic structure XPS spectrum showed distinct silver peaks on thenanoparticlesrsquo surface An optical method that was based on surface plasmon resonance (SPR) was used to perform the green AgNPs aqueous ammonia sensing study Optical measurement facilitated the ammonia sensing study of Ag NPs that had beenprepared $e study also investigated the performance of the optical sensor thus adding validity to the study Also the researchsought to determine how the concentration of ammonia in ammonia sensing affects the Ag NPs that had been obtained$e studyobserved a linear relationship with R2 as the correlation factor which was equal to 09831 $is was observed from the ammoniaconcentration plot versus absorption ratio that suggested that there was a linear increase in absorption ratio with increase inammonia concentration $e study significance is that the room temperature optical ammonia sensor can be used in future formedical diagnosis in the detection of low levels of ammonia in biological fluid like sweat cerebrospinal fluid saliva plasma orbiological samples $is enhances the application of the technique in human biomedical applications

1 Introduction

Ammonia is produced by the process of nitrogen fixationdecomposition of organic compounds and natural exchangeof atmospheric gases [1ndash6] $e gas has broad applicationsincluding the pharmaceutical industry manufacture offertilizers production of explosives and manufacture ofplastics Ammonia is also used as a synthetic paper and in themanufacture and production of paper and large-scale foodrefrigeration [7ndash9] Ammonia also has detrimental effects onhuman health as it creates eye and skin irritation Highammonia concentration has been implicated in lung dis-orders and permanent blindness $e gas is hazardous tocrustaceans an aquatic species even in minimal concen-trations $e gas cannot be converted to compounds that areless toxic $e presence of ammonia in the body of humanscould be an indication of various diseases and disordersSome of the diseases and disorders that can be detected by

the presence of ammonia include kidney and liver collapsediabetes ulcers bacterial infections of the gut and cancer[10ndash14]

It is important to find effective ways of detecting thepresence of ammonia even at low concentration because ofits toxic nature [15ndash17] Various strategies of detecting thepresence of ammonia have been described on the basis ofNessler reaction and luminol-hypochlorite reaction [18 19]$ere are however several drawbacks that affect the ef-fective detection of dissolved ammonia Additional equip-ment is required in the ammonia detection process and therelated reactions produce toxic chemicals

Silver NPs has gained immense relevance in the recentpast in the detection of various chemicals through colori-metric sensing because of its effective optical features calledsurface plasmon resonance (SPR) [20ndash23] $e latter is anoptical phenomenon that is seen when the surface con-ducting electrons of Ag NPs are excited by electromagnetic

HindawiJournal of ChemistryVolume 2020 Article ID 4712130 11 pageshttpsdoiorg10115520204712130

radiation leading to incoherent resonance oscillation withinthe particle [24 25] When the environment is manipulatedthrough a change in reflective index of the medium sur-rounding the particles and the metal surface moleculesadsorption absorbance change in near-infrared and visiblewavelength regions is seen in UV-vis spectrometry and isalso visible by naked eyes in certain situations [26 27]

$e colorimetric sensing of Ag NPs has been reported byvarious researchers Silver NPs were synthesized via peachgum polysaccharides by Yang et al [28] $e NPs that wereobtained from the procedure exhibited color changes frombrown to colorless for a detection limit of 0035mM forhydrogen peroxide $e Ag NPs were synthesized via Ficusamplissima leaf extract under direct sunlight by Manivel andIlanchelian [29] $e synthesized NPs were used for sensingmercury ion In the presence of Hg2+ the yellow silver NPScolloids changed color to become colorless with varying pHlevels from 32 to 85 Silver NPs were prepared using solublestarch and formamidine sulfinic acid by Song et al [30] $eAg NPs that were produced exhibited calorimetric sensingfor various metal ions $ere was a distinct color change forCr3+ from yellow to orange yellow to colorless for Fe3+ andHg2+ and yellow to pink for Al3+ Various studies onammonia detection have been conducted in the recent pastOne example is Dubas and Pimpanrsquos [31] study whereammonia sensing of Ag NPs was analyzed and stabilized bypoly(methacrylic acid) and sodium borohydride$ere was adistinct change of color from purple to yellow following theaddition of a solution of ammonia at a limit of detection of5 ppm Detsri and Popanyasak [32] used a technique oflayer-by-layer deposition to present the composite Ag NPSthin films as well as polyaniline $ere was a change of colorfrom orange-red to yellow when the films were exposed toammonia solution

Some of the chemicals in these works used to synthesizeAg NPs were however toxic to the environment and excesschemicals were required to facilitate the reaction processNatural products are of great interest particularly thosederived from plants Natural biopolymers for instance playa significant role in nanotechnology $is shows a greatpotential in various applications such as sensors adsorptioncatalysis and antimicrobial activity [33ndash35] through greenchemicals like polysaccharides sugar plant extract andascorbic acid [36] which acts as both a stabilizer and re-ducing agent $e disadvantage of using the chemicalshowever is that it requires a long reaction time for thecompletion of the reduction process for 20 h at roomtemperature [37] $is study reports green biosynthesis ofAg NPs through a durian fruit shell using a stabilizing andreducing reagent $e synthesized hybrid nanomaterial iseffective in the sensing and monitoring of ammonia solutionon the first encounter Detection of ammonia that is dis-solved is conducted on the basis of reagent color change inthe presence of ammonia as seen in the absorption spec-trometer $e material has the following specific charac-teristics the response time is quick the detection limitsshould be low and it should be ecofriendly and easilyavailable at a low cost operates optimally at room tem-perature requires no other reducing or stabilizing agents

functions optimally in an ambient environment and needsno air supply or oxygen and requires no external stimulisuch as illumination for reaction to initiate joule heatingUV-vis spectrophotometer was used in the monitoring ofthe kinetics of the synthesis of NPs while their morphologyand size were confirmed through different techniques ofanalysis $e sensing characteristics of the NPs solutionswere tested against the surging ammonia solution concen-trations between 500 and 3000 ppm through the monitoringof alterations in the amplitude and position of the LSPR witha UV-vis spectrophotometer

2 Experimental Procedure

21 Chemicals $e chemicals for the experiment weresourced differently Durian fruit was bought from a su-permarket in Taif Aqueous ammonia solution 25 wasprocured from Merck Germany while the sodium hy-droxide and silver nitrate were bought from Sigma AldrichUSA Besides these items the other additional constituentwas deionized water whose purpose was to prepare theaqueous solution for the investigations It is worth notingthat the elements were of analytical grade and were usedwholly without any further refinement or adulteration

22 Preparing Durian Fruit Extracts $e process involvedcollecting and thoroughly rinsing fresh durian fruit indistilled water 25 g was then picked and cut into tiny slicesbefore being smashed and ground in a grinding mixer byadding some 100ml of Millipore water Filtration of the rawextract was done using the Whatman filter paper (no 1)before centrifugation for 10minutes at 8000 rpm to get rid ofimpurities notably fiber Observations made indicated thatfollowing the centrifugation a clear or transparent extractwas obtained and the measure of viscosity was 087mPas$e aqueous solution was stored in a refrigerator to be usedlater

23 Silver Nanoparticles Synthesis For this experiment90ml of 10minus3M of silver nitrate aqueous solution was mixedwith 10ml of the extract $is was followed by adding so-dium hydroxide droplets while stirring to regulate the pH to10 $e mixture was put in a dark room for several hours tosettle $e solution was intermittently subjected to UV-visspectroscopy measurements to gauge how the Ag NPs formAmmonia sensing was then tested by further characterizingthe synthesized silver nanoparticles $ose nanoparticlesthat remained were placed in amber bottles and stored atroom temperature in a dark room

24 Characterizing Synthesized Silver Nanoparticles By us-ing the UV-visible absorption spectrometer specifically theSpecord S100 from Analytica Jena GmbH the optical ab-sorption spectra of these elements can be obtained In thiscase the spectra were collected at room temperature be-tween 350 and 800 nm with an instrument resolution of1 nm $e study of the structure of these Ag nanoparticles is

2 Journal of Chemistry

done using a scanning electron microscope model JEOLJSMndash6390LV Using this microscope thin films of thesample were placed on grids that are copper carbon coatedand thereafter the recording of the images was done $emorphology of the particles was further investigated on atransmission electron microscope (TEM) by first collectingand washing them in ethanol and water before centrifu-gation at 15000 rpm$is was repeated a number of times toensure that the protective shell of the fruit extract is removedto avail the biomolecules therein Furthermore the ele-mental silver that is existent in the sample was subjected toenergy dispersive spectroscopy (EDS) together with TEMAn X-ray diffractometer model RIGAKU MINIFLEX withCu-Kα radiation line λ 15405 A was used to determine theXRD patterns of the samples in a structural analysisComplete scans of 2θ 20degndash80deg with a step size of 005deg areconducted and the photoelectronic spectroscopy modelnumber XPS ESCALAB 210 was used to conduct the col-lection of silver from the surface of the nanoparticles

25 0e Test for Sensing Ammonia $e experiment wasconducted by mixing 1 ml of ammonia aqueous solutionwith 1 ml of silver nanoparticles $en different concen-trations of ammonia in a constant range between 0 and 3000were mixed with an aqueous solution of 25 ammoniaObservations made included a change of color detected bynaked eye and the detection of SPR nanoparticles when UV-vis spectrophotometer was used A spectral decline wasobserved on increase of ammonia concentrate at differentlevels Further there was a remarkable decrease in the UV-vis spectrum when the quantity of ammonia was increased$e discussion section highlights these absorption intensityvariations as well as their related processes at length

3 Results and Discussion

31 Formation of Green Silver Nanoparticles Simple one-step reproducible cost-effective high yield and envi-ronment friendly NPs through green synthesis are be-coming widespread and in high demand as a solution for aglobal problem together with other environmental con-cerns [38ndash41] $is study carried out a green synthesis ofAg NPs using durian fruit shell extract $e most prevalentmethod for preparing stable Ag NPs is chemical reductionwhere colloidal dispersion occur in organic solvents orwater [42] Colloidal Ag with NPs particles of differentdiameters are yielded from the reduction of the Ag ions inaqueous solution [43] $e initial reduction of severalcomplexes with silver ions leads to Ag atoms formation$e reaction is followed by the agglomeration of the metalions into oligomeric clusters [44ndash47] $e solutions havean intense band of 380ndash400 nm and a yellow color when thecolloidal particles are smaller than the visible lightwavelength $e intense band could be lesser than thesmaller bands with longer wavelengths in the absorptionspectrum [48] $e Ag NPs synthesis involves three keysteps that are subject to evaluation on the basis of theperspectives of green chemistry $e steps include solvent

media selection selection of reducing agents that areenvironmentally benign and selection of substances thatare not toxic to stabilize the silver NPs $e greenchemistry method of synthesizing Ag NPs throughchemical reduction therefore has been widely used in thisstudy

On adding NaOH (1M) drop-wise to the mixture ofdurian organic product shell containing Ag+ particles(AgNO3 1 mM) the color of the response blend becameyellowish and afterwards dim dark colored $e forma-tion of silver nanoparticles was proved by the adjustmentin color of the arrangement after expansion of AgNO3from colorless to light yellowish shading at that point tothe dim darker shading Subsequent to adding silvernitrate arrangement to concentrate of durian organicproduct shell the shades of the blends changed fromcolorless to orange-yellow as shown in Figure 1(a)demonstrating the development of silver nanoparticles$e colour of the solutions got darker with increase intime which means the higher amount of silver nano-particles were obtained $e various shades of silvernanoparticles are identified with the excitation impact ofsurface plasmon resonance [49ndash51]

Development of silver nanoparticles by decreasingAg+ particles was deliberately checked by UV-vis spec-troscopy at 30 60 90 120 150 180 and 210min Byrecording the changes in absorbance as a function oftime the kinetic of development of silver nanoparticlesformation was checked [52 53] and the accumulation ofthe absorbance spectra is shown in Figure 1(b) $isinformation uncovers a few significant discoveries whichcan be exhibited as follows there was an increase in theheight of the peak with increase of time (i) At the be-ginning of the period of response length (after 90 min)the plasmon band is expanded and straightforward testfor silver particle shows low transformation of silverparticles to metallic silver nanoparticles at this span (ii)drawing out the response term up to 180min promptsremarkable upgrade in the plasmon force demonstratingthat a lot of silver particles are diminished and utilized forbunch development and (iii) further increment in theresponse term up to 210min results in negligible dec-rement in the retention power which could be credited tosome conglomeration of the shaped silver nanoparticles$e last absorbance pinnacle of the nanoparticles ar-rangement stands out unequivocally from the normalabsorbance most extreme at 394 nm which is usuallyexhibited as the quality of fruitful silver nanoparticlesamalgamation $e absorbance peak normally emergesbecause of the excitation of confined surface plasmonmotions of the conduction electrons if there should arisean occurrence of valuable metal nanoparticles for ex-ample gold and silver

$e arrangement of Ag NPs from Ag+ particlesisstarted by the compound responses within polysac-charide (polyols) with the general formula Cx (H2O)y andascorbic corrosive (C6H8O6) as decreasing agents bothpresent in durian organic product shell extract [54] $egeneral response can be composed as follows

Journal of Chemistry 3

2Ag++ Cx H2O( 1113857y + H2O⟶ 2Agdeg + CxH2yminus1Oy+11113872 1113873

minus

+ 3H+

(1)

2Ag++ C6H8O6⟶ 2Agdeg

+ C6H8O6(diydroxy ascorbic acid) + 2H+

(2)

It is clear that every increase in the concentration of OHminus

ions forwarded the reaction and resulted in an increase in theproduction of silver nanoparticles $is was confirmed by ahigher pH 10 yield

32 Characteristics of the Green Synthesized SilverNanoparticles $e mixture of the reaction was centrifugedwith 4000 rpm for 20min and the precipitant was centri-fuged after being washed with running water At that pointthe pellets were gathered and dried in hot air oven at alegitimate temperature of 35ndash40degC Dried nanoparticles weregathered and utilized for additional portrayal and applica-tion studies Nanoparticles are for the most part portrayedby contributing their size shape and surface territoryHomogeneity in these properties brings about the pro-gression in utilization of nanoparticles $e portrayal ofsilver nanoparticle is performed by utilizing different in-strumental procedures

Morphological character and size subtleties of theincorporated silver nanoparticle were given by SEM pic-tures Figure 2(a) $is size variety in the nanoparticles isbecause of the nearness of proteins or different atoms fromextract which were bound at the outside of the nano-particles Furthermore the outcome demonstrated thatthe blended silver nanoparticles were round fit as a fiddleWe have completed transmission electron minute (TEM)

concentrate to get data about the inward structure (sizeand morphology) of the biosynthesized Ag nanoparticlesOur TEM picture in Figure 2(b) likewise shows that the thesilver nanoparticles fabricated after 210 min utilizing fruitextracts are covered by a thin layer of capping materialsTEM picture shows circular particles of small sizeFigure 2(c) shows the molecule size circulation histogramof the size conveyance of biosynthesized Ag nanoparticlesestimated from TEM study $e TEM figure outlines thatthose nanoparticles measurement fluctuate between 20and 30 nm$e normal distance across silver nanoparticleswas seen as around 25 nm with practically circular fit as afiddle shape and monodispersed in nature ComparativeSAED design was acquired with silver nanoparticlesblended utilizing aloe vera [55]

EDS range recorded from the silver nanoparticles is shownin Figure 2(d) separately EDS profile shows solid silver sign$is pinnacle was framed because of the impact of surfaceplasmon reverberation of green-blended nanoparticle [56] Itwas shown that arrangement of silver nanoparticles utilizingnatural product shell separates Other minor pinnacles forexample C and O were seen at different retention vitalitylevels $ese may happen from organic product shell extractbecause of the nearness of moieties of phytochemicals con-stituents $ese parts engaged with the balancing out andtopping agent on the outside of nanoparticles Comparableoutcomes were accounted for on green blend of silver nano-particles [57] Together with TEM pictures Shankar et al [58]detailed that nanoparticles combined utilizing plant extractsare encompassed by a slight layer of some topping naturalmaterial from organic product

$e spectrum of XPS displays a characteristic Ag peak onthe NPs surface which indicates that Ag NPs are synthesizedsuccessfully through the durian fruit extraction as shown in

0min 30min 60min 90min 120min 150min 180min 210min

(a)A

bsor

banc

e (au

)

0min30min60min90min

120min150min180min210min

ndash05

00

05

10

15

20

25

30

35

500 600 700 800400Wavelength (nm)

(b)

Figure 1 $e appearances of silver nitrate solution and AgNPs colloids synthesized (a) and the UV-vis spectra of the formed AgNPs atvarious times of 0 30 60 90 120 150 180 and 210min (b)


Figure 2(e) When the reaction is starting the Ag+ are re-duced precipitating the formation of Ag atoms$e nuclei ofthe Ag atoms rapidly form small NPs due to the reducedcapping agent that is physically adsorbed on the NPs surface$e small NPs that are formed aggregate to form larger NPsdue to a higher surface energy and high density of thesmaller NPs at the start of the chemical process $e largeparticles that are formed however are unstable and can bedegraded into smaller components As the reaction pro-ceeds more Ag+ are reduced to form Ag atoms thus causinga decrease at the start and a later increase at particularreaction time and then finally stabilizing [59]

Figure 2(f ) shows the patterns of X-ray diffraction of theAg NPs $e peaks are seen at various values which include2θ values 378deg 4396deg 6434deg and 7748deg that pertain AgNPs $e planes (111) (200) (220) and (311) from theindexed peaks correspond to the silver face-centered cubicstructure (JCPDS no893722) $e Ag NPs gram size wasestimated from the XRD width peak at 2θ 378deg Schererrsquosformula was used to estimate the average NP size which wasfound to be 21 nm Average grain size of the nanoparticlewas found to be 21 nm using Schererrsquos formuladavg ((09λ)β cos θ) where λ is the wavelength of CuKα1radiation davg i is the average size of the grain β is the entire

200nm

(a)

100nm

(b)

30ndash40

20ndash30

50ndash60

Particle size (nm)

(c)

1 3 5 7 9keV

(d)

360 365 370 375 380Binding energy (eV)

(e)

35 45 55 65 752θdeg

111

200

220 311

(f )

Figure 2 Characterization of silver nanoparticles formed with 90mL of 10ndash3M aqueous AgNO3 solution and durian fruit shell (a) SEMmicrograph (b) TEM micrograph (c) diameter particles diameter with counts and (d) EDS spectrum (e) XPS spectrum and (f) XRDanalysis


width at half maximum (FWHM) and θ represents the angleof diffraction [60ndash62]

33 Ammonia Sensor Properties Innovative technologieshave been adopted in conducting the research for ammoniadetection using ammonia sensors because of its functionalapplications in the industrial sector and its toxic nature toboth humans and other living beings $e wide applicationsof ammonia in industrial applications create a lot of demandfor the development of ammonia sensors as they are used forthe purposes of its monitoring in a diverse range of appli-cations [63ndash65] In order to obtain the UV-vis spectra foreach level the color combinations were observed as indi-cated in Figure 3(a) with the color of the solution changingfrom brown to clear With an increase in the concentrationof ammonia the color of the Ag NPs changes and the de-creases in the intensity of absorption are detectable by thenaked eye

Optical measurement is the most ideal way of con-ducting a sensor study of an ammonia solution Ag NPabsorbance spectra studies contain different levels of am-monia concentrations and are documented as a function ofvarying concentrations of ammonia ranges between 0 and3000 ppm as indicated in Figure 3(b) while the values ofammonia concentration absorption is indicated inFigure 3(c) Different silver nanoparticles colloidal solutionsare required for each measurement Remarkably the LSPRhighest concentration for Ag NPs moves from 391 nm to403 nm when ammonia solution is added to it $e differ-ence in the Ag NPs SPR band is caused by the change in thesurrounding mediumrsquos dialectic constant and the distance ofinterparticles [66]

Efforts for enhancement include data processing andconsidering the absorbance ratio of ammonia concentration(Abs391403) as indicated in Figure 4 According to the ratioof absorbance the concentration of ammonia linearityranges from 500 to 3000 ppm In such cases the ration ofabsorbance for (Abs391Abs403) is investigated and indi-cated as an element of ammonia concentration illustrating arelationship that is linear with a correlation factor R2 whichis an equivalent of 09831 a figure which compares favorablyto previous reports [7] Absorbance ratios outputs a con-centration of ammonia linearity within the range of 500 to3000 ppm and this therefore is an illustration that ananalysis of the absorption spectra of 391 nm is possible andthe set Ag NPs are used as an optical sensor$erefore theseresults enable us to make a conclusion that Ag NPs have ahigh capability to detect lower ammonia concentrationswithin solutions (of up to 3000 ppm from our study) andthus are ideal optical sensors that we can deploy in ammoniasensing

In the determination of the time needed to complete acomplexing reaction commonly referred to as the retentiontime the silver nanoparticles colloidal solution is measuredin a test tube where various ammonia levels are then addedin the range of 1000 2000 and 3000 ppm Observing theresultant output the maximum absorbance recorded usingthe UV-vis spectrophotometer is shown in Figure 5 In

Figure 6 one requires a minimum of 25 nm to gain ap-proximately 95 completion of the complex reactionnotwithstanding the amount of ammonia used

34 Reaction of NPs with Ammonia When Ag+ ions aremixed with ammonia a coordination complex Ag (NH3)2+ isformed When silver colloids come into contact with anammonia solution Ag (NH3)2+ they form a coordinationcomplex between them increasing the Ag NPs surfacecharge which in turn creates a repulsion force between theparticles thereby increasing the water content in the sur-rounding $e outcome isolates hydrophilic particles with ablue shift spectrum as shown in Figure 7 Nanoparticlesdecolorization occurs as a result of the manipulation of theAg NPs SPR through the formation of the Ag (NH3)2+Complex Ag (NH3)2+ forms Ag NPs to break away throughtheir transformation into smaller nanoparticles with blueshift $e formed complex diminishes the quantity of AgNPs thereby successfully decreasing its color intensityConsequently the plasmonic bands of silver nanoparticlesare directly affected by the amount of Ag (NH3)2+ $eimplication of this is that the more the ammonia the higherthe amounts of Ag (NH3)2+ complex and hence the lower theAg NPs amount $erefore a reduction in a silver nano-particles plasmonic band is unavoidable [67 68]

35 Applications of Spectrophotometric Method $e devel-oped sensors need to be tested for their applicability indetermining ammonia levels in actual samples and thereforethe most efficient way to do this is by using the spectro-photometric approaches To achieve this two samples ofmarine water and bottled water are spiked with varyingconcentrations of ammonia and an analysis is done $eresults that are used for determining ammonia and recoveryfor the spike samples are as indicated in Table 1 For each ofthe three concentrations three measurements are con-ducted giving a good outcome between the value estima-tions in the analysis in the spectrophotometric approaches$e recovery is recorded at the range of 8966ndash10144Outcomes of metallic nanoparticles unique LSPR propertiesindicate that they are simple and of low cost have a quickresponse time and great reproducibility and are highlysensitive characteristics which make them very useful

36 Stability of the FabricatedAgNPs Figure 8 shows a studythat was conducted for four months Its outcome indicatesthat stability is constant for the whole duration of fourmonths Likewise the fabricated silver nanoparticles ab-sorbance decreases to 2582 au while the wavelengthslightly moves effectively from 391 nm to 394 nm Whenpreparing the silver nanoparticles mixture large-sized ag-glomerates are formed through the VanderWaalsrsquos principleor the Colombrsquos force from the individual particles A re-ducing agent is added to the mixture to inhibit the ag-glomeration of the small particles Usually the durian fruitshell extract is used as the stabilizing reducing reagent as itcreates a shielding layer on the surface of the particle ensued


500ppm

1000ppm

1500ppm

2000ppm

2500ppm

3000ppmControl

(a)

Abs

orba

nce (

au)

ndash05

00

05

10

15

20

25

30

500 600 700 800400Wavelength (nm)

Control500 ppm1000 ppm1500 ppm

2000 ppm2500 ppm3000 ppm

(b)

Abs

orba

nce (

au)

00

05

10

15

20

25

30

500 1000 1500 2000 2500 3000 35000Ammonia concentration (ppm)

(c)

Figure 3 $e effect of ammonia on the green fabricated silver nanoparticles different levels of ammonia were added to the colloidalsolution of Ag NPs containing a constant level of the nanoparticles (a) Change in the UV-visible spectra of silver nanoparticles as a functionof different concentrations of ammonia from 0 to 3000 ppm (b) Plot of absorbance versus ammonia concentration (c)

2

3

4

5

6

7

8

9

Abs3

91A

bs40

3


Figure 4 Absorbance ratio at 391 nm and 403 nm which displays a linear relationship as a function of different ammonia concentrations(500 ppm to 3000 ppm) with a correlation factor R2 equal to 09831


5min10min15min20min



ndash01

00

01

02

03

04

05

06

Abso

rban

ce (a

u)

600 800 1000400Wavelength (nm)

(a)

5min10min15min20min



ndash01

00

01

02

03

04

05

06

Abso

banc

e (au

)

500 600 700 800400Wavelength (nm)

(b)

5min10min15min20min



00

01

02

03

04

05

06

Abso

rban

ce (a

u)

500 600 700 800400Wavelength (nm)

(c)

Figure 5 Effect of time (5ndash60min) on the absorbance of the green fabricated silver nanoparticles after adding different amounts ofammonia solution (a) 1000 ppm (b) 2000 ppm and (c) 3000 ppm

0

2

4

6

8

10

12

14

16

A39

1A

403

10 20 30 40 50 60 700Time (min)

Figure 6 Absorbance ratio of the fabricated silver nanoparticles versus elapsed time in the presence of different concentrations of ammonia0 ppm (bull) 1000 ppm () 2000 ppm () 3000 ppm (◼)


by a strong absorption of the reducing agent on the surfaceof the silver nanoparticles thus ensuring that better stabi-lization is achieved

4 Conclusions

$e current study uses the durian fruit shell extract to syn-thesize silver nanoparticles from silver nitrate a technique thatis commonly adaptable in principles of green chemistry $edurian fruit extract performs the functions of stabilizing andreducing the synthesized silver nanoparticles $e durian fruitshell agent used influences the synthesis of the nanoparticles toincrease with the silver nitrate concentration and the reactiontime Since there is a possibility of controlling the size of thenanoparticles this method is ideal for large scale industrialapplications of monodispersed and circular nanoparticles ofapproximately 25nm given the fact that low-cost biopolymer isavailable $e decline in the plasmonic features of the Ag NPscan be attributed to the presence of the oxidizing agent in the

ammonia solution which has the ability to coagulate into Ag(NH3)2+ with Ag ions $e characteristics of the Ag NPs makeit possible for the ammonia colorimetric detection and couldtherefore be used for optical sensing in healthcare diagnosticsto detect low levels of ammonia in the human body $eseattributes include the localized SPR property simplicity sen-sitivity affordability and its quick turnaround time

Data Availability

$e data used in this paper are available upon reasonablerequest from the corresponding author

Additional Points

No animalshumans were used for studies that are the basisof this research

Conflicts of Interest

$e author declares that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

$e author acknowledges the support of Taif UniversityResearchers Supporting Project number TURSP-2020136Taif University Taif Saudi Arabia

References

[1] P Warneck Chemistry of the Natural Atmosphere ElsevierAmsterdam Netherlands 1999

[2] E Abatenh B Gizaw Z Tsegaye and T Genene ldquoMicrobialfunction on climate change-a reviewrdquo Open Journal of En-vironmental Biology vol 3 no 1 pp 1ndash7 2018

[3] C E BoydNitrogen inWater Quality pp 269ndash290 SpringerBerlin Germany 2020

[4] K Rousk M Vestergard and S Christensen ldquoAre nitrousoxide emissions and nitrogen fixation linked in temperatebogsrdquo Soil Biology and Biochemistry vol 123 pp 74ndash79 2018

[5] T Shah S Lateef and M A Noor ldquoCarbon and nitrogencycling in agroecosystems an overviewrdquo in Carbon and

Silver nanoparticles Silver - ammonia complex

SNPsNH3

H3N-Ag-NH3

Figure 7 Reaction mechanism of silver nanoparticles with ammonia

Table 1 Determination of ammonia in real sample using the synthesized silver nanoparticles

Type of sample Ammonia added (ppm) Ammonia found (ppm) Recovery ()

Bottle water 900 913plusmn 06 101441800 1811plusmn 19 10061

Marine water 900 807plusmn 08 89661800 1689plusmn 21 9383

Abs

orba

nce (

au)

ndash05

00

05

10

15

20

25

30

500 600 700 800400Wavelength (nm)

1st m2nd m

3rd m4th m

Figure 8 UV-vis spectra of the fabricated silver nanoparticles tocheck the stability of the fabricated silver nanoparticles for fourmonths


Nitrogen Cycling in Soil pp 1ndash15 Springer Berlin Germany2020

[6] X Yang F Ling J Su et al ldquoInsights into the role of cationvacancy for significantly enhanced electrochemical nitrogenreductionrdquo Applied Catalysis B Environmental vol 264Article ID 118477 2020

[7] L Chetia D Kalita and G A Ahmed ldquoSynthesis of Agnanoparticles using diatom cells for ammonia sensingrdquoSensing and Bio-Sensing Research vol 16 pp 55ndash61 2017

[8] Y Jegal and Y Kim ldquoIndustrial chemicals and acute lunginjury with a focus on exposure scenariosrdquo Current Respi-ratory Medicine Reviews vol 12 no 1 pp 44ndash55 2016

[9] J G Speight Handbook of Petrochemical Processes CRCPress Boca Raton FL USA 2019

[10] C Pijolat C Pupier M Sauvan G Tournier and R LalauzeldquoGas detection for automotive pollution controlrdquo Sensors andActuators B Chemical vol 59 no 2-3 pp 195ndash202 1999

[11] Y Chang Z Zou C Deng et al ldquo$e importance of vehicleemissions as a source of atmospheric ammonia in themegacity of Shanghairdquo Atmospheric Chemistry and Physicsvol 16 no 5 pp 3577ndash3594 2016

[12] W Ament J R Huizenga E Kort T W Van Der MarkR G Grevink and G J Verkerke ldquoRespiratory ammoniaoutput and blood ammonia concentration during incrementalexerciserdquo International Journal of Sports Medicine vol 20no 2 pp 71ndash77 1999

[13] L NarasimhanW Goodman and C K N Patel ldquoCorrelationof breath ammonia with blood urea nitrogen and creatinineduring hemodialysisrdquo Proceedings of the National Academy ofSciences vol 98 no 8 pp 4617ndash4621 2001

[14] R Alam ldquoStudy on removal of ammonia from the waste waterof Fenchuganj natural gas fertilizer factoryrdquo Dissertation$esis Bangladesh University of Engineering and Technol-ogy Dhaka Bangladesh 2006

[15] K Zakrzewska ldquoMixed oxides as gas sensorsrdquo 0in SolidFilms vol 391 no 2 pp 229ndash238 2001

[16] M Sahm A Oprea N Barsan and U Weimar ldquoWater andammonia influence on the conduction mechanisms in pol-yacrylic acid filmsrdquo Sensors and Actuators B Chemicalvol 127 no 1 pp 204ndash209 2007

[17] Y Shen and P Prasad ldquoNanophotonics a new multidisci-plinary frontierrdquo Applied Physics B vol 74 no 7-8pp 641ndash645 2002

[18] C Molins-Legua S Meseguer-Lloret Y Moliner-Martinezand P Campıns-Falco ldquoA guide for selecting the most ap-propriate method for ammonium determination in wateranalysisrdquo TrAC Trends in Analytical Chemistry vol 25 no 3pp 282ndash290 2006

[19] J Li and P K Dasgupta ldquoChemiluminescence detection witha liquid core waveguide determination of ammonium withelectrogenerated hypochlorite based on the luminol-hypo-chlorite reactionrdquo Analytica Chimica Acta vol 398 no 1pp 33ndash39 1999

[20] B Wiley Y Sun B Mayers and Y Xia ldquoShape-controlledsynthesis of metal nanostructures the case of silverrdquo Chem-istryndashA European Journal vol 11 no 2 pp 454ndash463 2005

[21] M-R Xie Y Cai Y-Q Liu and Z-Y Wu ldquoSensitive col-orimetric detection of Pb2+ by geometric field amplificationand surface plasmon resonance visualizationrdquo Talantavol 212 Article ID 120749 2020

[22] I C Sulaiman B W Chieng M J Osman et al ldquoA review oncolorimetric methods for determination of organophosphatepesticides using gold and silver nanoparticlesrdquo MicrochimicaActa vol 187 no 2 pp 1ndash22 2020

[23] S Prajapati ldquoNanotechnology-based sensorsrdquo in Biopolymer-Based Formulations pp 237ndash262 Elsevier AmsterdamNetherlands 2020

[24] K A Willets and R P Van Duyne ldquoLocalized surfaceplasmon resonance spectroscopy and sensingrdquo Annual Re-view of Physical Chemistry vol 58 pp 267ndash297 2007

[25] P Slepicka N Slepickova Kasalkova J Siegel Z Kolska andV Svorcik ldquoMethods of gold and silver nanoparticles prep-arationrdquo Materials vol 13 no 1 pp 1ndash22 2020

[26] T Ritthichai and V Pimpan ldquoAmmonia sensing of silvernanoparticles synthesized using tannic acid combined withUV radiation effect of UV exposure timerdquo Journal of KingSaud University-Science vol 31 no 2 pp 277ndash284 2019

[27] S Zeng D Baillargeat H-P Ho and K-T Yong ldquoNano-materials enhanced surface plasmon resonance for biologicaland chemical sensing applicationsrdquo Chemical Society Reviewsvol 43 no 10 pp 3426ndash3452 2014

[28] N Yang X-F Wei and W-H Li ldquoSunlight irradiation in-duced green synthesis of silver nanoparticles using peach gumpolysaccharide and colorimetric sensing of H2O2rdquo MaterialsLetters vol 154 pp 21ndash24 2015

[29] P Manivel and M Ilanchelian ldquoSelective and sensitive col-orimetric detection of Hg2+ at wide pH range using greensynthesized silver nanoparticles as proberdquo Journal of ClusterScience vol 28 no 3 pp 1145ndash1162 2017

[30] J Song O Ma S Zhang Y Guo and C Dong ldquoPreparationof silver nanoparticles reduced by formamidinesulfinic acidand its application in colorimetric sensorrdquo Journal of ClusterScience vol 27 no 4 pp 1203ndash1212 2016

[31] S T Dubas and V Pimpan ldquoGreen synthesis of silvernanoparticles for ammonia sensingrdquo Talanta vol 76 no 1pp 29ndash33 2008

[32] E Detsri and J Popanyasak ldquoFabrication of silver nano-particlespolyaniline composite thin films using layer-by-layerself-assembly technique for ammonia sensingrdquo Colloids andSurfaces A Physicochemical and Engineering Aspects vol 467pp 57ndash65 2015

[33] S Pandey ldquoA comprehensive review on recent developmentsin bentonite-based materials used as adsorbents for waste-water treatmentrdquo Journal of Molecular Liquids vol 241pp 1091ndash1113 2017

[34] S Pandey ldquoHighly sensitive and selective chemiresistor gasvapor sensors based on polyaniline nanocomposite a com-prehensive reviewrdquo Journal of Science Advanced Materialsand Devices vol 1 no 4 pp 431ndash453 2016

[35] S Pandey and K K Nanda ldquoAu nanocomposite basedchemiresistive ammonia sensor for health monitoringrdquo AcsSensors vol 1 no 1 pp 55ndash62 2016

[36] S Ganaie T Abbasi J Anuradha and S A Abbasi ldquoBio-mimetic synthesis of silver nanoparticles using the amphib-ious weed ipomoea and their application in pollutioncontrolrdquo Journal of King Saud University-Science vol 26no 3 pp 222ndash229 2014

[37] P Raveendran J Fu and S L Wallen ldquoCompletely ldquogreenrdquosynthesis and stabilization of metal nanoparticlesrdquo Journal ofthe American Chemical Society vol 125 no 46pp 13940-13941 2003

[38] P Tippayawat N Phromviyo P Boueroy andA Chompoosor ldquoGreen synthesis of silver nanoparticles inaloe vera plant extract prepared by a hydrothermal methodand their synergistic antibacterial activityrdquo PeerJ vol 4Article ID e2589 2016

[39] A Allafchian S Z Mirahmadi-Zare S A H Jalali andM R Vahabi ldquoGreen synthesis of silver nanoparticles using


phlomis leaf extract and investigation of their antibacterialactivityrdquo Journal of Nanostructure in Chemistry vol 6 no 2pp 129ndash135 2016

[40] M E Palanco K Bo Mogensen M Guhlke Z HeinerJ Kneipp and K Kneipp ldquoTemplated green synthesis ofplasmonic silver nanoparticles in onion epidermal cellssuitable for surface-enhanced Raman and hyper-Ramanscatteringrdquo Beilstein Journal of Nanotechnology vol 7 no 1pp 834ndash840 2016

[41] S Ahmed Saifullah M Ahmad B L Swami and S IkramldquoGreen synthesis of silver nanoparticles using azadirachtaindica aqueous leaf extractrdquo Journal of Radiation Researchand Applied Sciences vol 9 no 1 pp 1ndash7 2016

[42] T Das A Pramanik and D Haldar ldquoOn-line ammoniasensor and invisible security ink by fluorescent zwitterionicspirocyclic meisenheimer complexrdquo Scientific Reports vol 7no 1 pp 1ndash12 2017

[43] E Alzahrani ldquoChitosanmembrane embedded with ZnOCuOnanocomposites for the photodegradation of fast green dyeunder artificial and solar irradiationrdquo Analytical ChemistryInsights vol 13 Article ID 1177390118763361 2018

[44] A Hebeish A El-Shafei S Sharaf and S Zaghloul ldquoNovelprecursors for green synthesis and application of silvernanoparticles in the realm of cotton finishingrdquo CarbohydratePolymers vol 84 no 1 pp 605ndash613 2011

[45] L Jeong andW H Park ldquoPreparation and characterization ofgelatin nanofibers containing silver nanoparticlesrdquo Interna-tional Journal of Molecular Sciences vol 15 no 4pp 6857ndash6879 2014

[46] M Rele S Kapoor G Sharma and T Mukherjee ldquoReductionand aggregation of silver and thallium ions in viscous mediardquoPhysical Chemistry Chemical Physics vol 6 no 3 pp 590ndash595 2004

[47] M Kooti S Saiahi and H Motamedi ldquoFabrication of silver-coated cobalt ferrite nanocomposite and the study of itsantibacterial activityrdquo Journal of Magnetism and MagneticMaterials vol 333 pp 138ndash143 2013

[48] M Vijayakumar K Priya F T Nancy A Noorlidah andA B A Ahmed ldquoBiosynthesis characterisation and anti-bacterial effect of plant-mediated silver nanoparticles usingArtemisia nilagiricardquo Industrial Crops and Products vol 41pp 235ndash240 2013

[49] M E Khan A Mohammad and M H Cho ldquoNanoparticlesbased surface plasmon enhanced photocatalysisrdquo in GreenPhotocatalysts pp 133ndash143 Springer Berlin Germany 2020

[50] E Alzahrani ldquoColorimetric detection based on localizedsurface plasmon resonance optical characteristics for sensingof mercury using green-synthesized silver nanoparticlesrdquoJournal of Analytical Methods in Chemistry vol 2020 ArticleID 6026312 2020

[51] E Alzahrani ldquoEco-friendly production of silver nanoparticlesfrom peel of tangerine for degradation of dyerdquoWorld Journalof Nano Science and Engineering vol 5 no 1 pp 10ndash16 2015

[52] E Alzahrani ldquoColorimetric detection based on localisedsurface plasmon resonance optical characteristics for thedetection of hydrogen peroxide using acacia gumndashstabilisedsilver nanoparticlesrdquo Analytical Chemistry Insights vol 12Article ID 1177390116684686 2017

[53] E Alzahrani and K Welham ldquoOptimization preparation ofthe biosynthesis of silver nanoparticles using watermelon andstudy of its antibacterial activityrdquo International Journal ofBasic and Applied Sciences vol 3 no 4 2014

[54] I H Chowdhury S Ghosh R Mouni and M Kanti NaskarldquoGreen synthesis of water-dispersible silver nanoparticles at

room temperature using green carambola (star fruit) extractrdquoJournal of Sol-Gel Science and Technology vol 73 no 1pp 199ndash207 2015

[55] S P Chandran M Chaudhary R Pasricha A Ahmad andM Sastry ldquoSynthesis of gold nanotriangles and silvernanoparticles using aloevera plant extractrdquo BiotechnologyProgress vol 22 no 2 pp 577ndash583 2006

[56] P Magudapathy P Gangopadhyay B K PanigrahiK GM Nair and S Dhara ldquoElectrical transport studies of Agnanoclusters embedded in glass matrixrdquo Physica B Con-densed Matter vol 299 no 1-2 pp 142ndash146 2001

[57] A Gomathi S R Xavier Rajarathinam A Mohammed Sadiqand S Rajeshkumar ldquoAnticancer activity of silver nano-particles synthesized using aqueous fruit shell extract ofTamarindus indica on MCF-7 human breast cancer cell linerdquoJournal of Drug Delivery Science and Technology vol 55Article ID 101376 2020

[58] S S Shankar A Rai A Ahmad and M Sastry ldquoRapidsynthesis of Au Ag and bimetallic Au corendashAg shell nano-particles using neem (Azadirachta indica) leaf brothrdquo Journalof Colloid and Interface Science vol 275 no 2 pp 496ndash5022004

[59] M Ismail M I Khan K Akhtar et al ldquoBiosynthesis of silvernanoparticles a colorimetric optical sensor for detection ofhexavalent chromium and ammonia in aqueous solutionrdquoPhysica E Low-Dimensional Systems and Nanostructuresvol 103 pp 367ndash376 2018

[60] H Bar D K Bhui G P Sahoo et al ldquoGreen synthesis of silvernanoparticles using latex of Jatropha curcasrdquo Colloids andSurfaces A Physicochemical and Engineering Aspects vol 339no 1ndash3 pp 134ndash139 2009

[61] D R Raj S Prasanth T V Vineeshkumar andC Sudarsanakumar ldquoAmmonia sensing properties of taperedplastic optical fiber coated with silver nanoparticlesPVPPVA hybridrdquo Optics Communications vol 340 pp 86ndash922015

[62] S Kaviya J Santhanalakshmi B Viswanathan J Muthumaryand K Srinivasan ldquoBiosynthesis of silver nanoparticles usingcitrus sinensis peel extract and its antibacterial activityrdquoSpectrochimica Acta Part A Molecular and BiomolecularSpectroscopy vol 79 no 3 pp 594ndash598 2011

[63] S Kannaiyan and A Gopal ldquoBiogenic synthesized silvercolloid for colorimetric sensing of dichromate ion and an-tidiabetic studiesrdquo Research on Chemical Intermediatesvol 43 no 5 pp 2693ndash2706 2017

[64] B Onida S Fiorilli A Borello G Viscardi D A McQuarrieand E Garrone ldquoMechanism of the optical response ofmesoporous silica impregnated with Reichardtrsquos dye to NH3and other gasesrdquo0e Journal of Physical Chemistry B vol 108no 43 pp 16617ndash16620 2004

[65] H S Mader and O S Wolfbeis ldquoOptical ammonia sensorbased on upconverting luminescent nanoparticlesrdquoAnalyticalChemistry vol 82 no 12 pp 5002ndash5004 2010

[66] M K Hedayati F Faupel and M Elbahri ldquoReview ofplasmonic nanocomposite metamaterial absorberrdquoMaterialsvol 7 no 2 pp 1221ndash1248 2014

[67] Z Khan J Hussain S Kumar A A Hashmi andM AMalikldquoSilver nanoparticles green route stability and effect of ad-ditivesrdquo Journal of Biomaterials and Nanobiotechnologyvol 2 no 4 p 390 2011

[68] A Amirjani and D H Fatmehsari ldquoColorimetric detection ofammonia using smartphones based on localized surfaceplasmon resonance of silver nanoparticlesrdquo Talanta vol 176pp 242ndash246 2018


radiation leading to incoherent resonance oscillation withinthe particle [24 25] When the environment is manipulatedthrough a change in reflective index of the medium sur-rounding the particles and the metal surface moleculesadsorption absorbance change in near-infrared and visiblewavelength regions is seen in UV-vis spectrometry and isalso visible by naked eyes in certain situations [26 27]

$e colorimetric sensing of Ag NPs has been reported byvarious researchers Silver NPs were synthesized via peachgum polysaccharides by Yang et al [28] $e NPs that wereobtained from the procedure exhibited color changes frombrown to colorless for a detection limit of 0035mM forhydrogen peroxide $e Ag NPs were synthesized via Ficusamplissima leaf extract under direct sunlight by Manivel andIlanchelian [29] $e synthesized NPs were used for sensingmercury ion In the presence of Hg2+ the yellow silver NPScolloids changed color to become colorless with varying pHlevels from 32 to 85 Silver NPs were prepared using solublestarch and formamidine sulfinic acid by Song et al [30] $eAg NPs that were produced exhibited calorimetric sensingfor various metal ions $ere was a distinct color change forCr3+ from yellow to orange yellow to colorless for Fe3+ andHg2+ and yellow to pink for Al3+ Various studies onammonia detection have been conducted in the recent pastOne example is Dubas and Pimpanrsquos [31] study whereammonia sensing of Ag NPs was analyzed and stabilized bypoly(methacrylic acid) and sodium borohydride$ere was adistinct change of color from purple to yellow following theaddition of a solution of ammonia at a limit of detection of5 ppm Detsri and Popanyasak [32] used a technique oflayer-by-layer deposition to present the composite Ag NPSthin films as well as polyaniline $ere was a change of colorfrom orange-red to yellow when the films were exposed toammonia solution

Some of the chemicals in these works used to synthesizeAg NPs were however toxic to the environment and excesschemicals were required to facilitate the reaction processNatural products are of great interest particularly thosederived from plants Natural biopolymers for instance playa significant role in nanotechnology $is shows a greatpotential in various applications such as sensors adsorptioncatalysis and antimicrobial activity [33ndash35] through greenchemicals like polysaccharides sugar plant extract andascorbic acid [36] which acts as both a stabilizer and re-ducing agent $e disadvantage of using the chemicalshowever is that it requires a long reaction time for thecompletion of the reduction process for 20 h at roomtemperature [37] $is study reports green biosynthesis ofAg NPs through a durian fruit shell using a stabilizing andreducing reagent $e synthesized hybrid nanomaterial iseffective in the sensing and monitoring of ammonia solutionon the first encounter Detection of ammonia that is dis-solved is conducted on the basis of reagent color change inthe presence of ammonia as seen in the absorption spec-trometer $e material has the following specific charac-teristics the response time is quick the detection limitsshould be low and it should be ecofriendly and easilyavailable at a low cost operates optimally at room tem-perature requires no other reducing or stabilizing agents

functions optimally in an ambient environment and needsno air supply or oxygen and requires no external stimulisuch as illumination for reaction to initiate joule heatingUV-vis spectrophotometer was used in the monitoring ofthe kinetics of the synthesis of NPs while their morphologyand size were confirmed through different techniques ofanalysis $e sensing characteristics of the NPs solutionswere tested against the surging ammonia solution concen-trations between 500 and 3000 ppm through the monitoringof alterations in the amplitude and position of the LSPR witha UV-vis spectrophotometer

2 Experimental Procedure

21 Chemicals $e chemicals for the experiment weresourced differently Durian fruit was bought from a su-permarket in Taif Aqueous ammonia solution 25 wasprocured from Merck Germany while the sodium hy-droxide and silver nitrate were bought from Sigma AldrichUSA Besides these items the other additional constituentwas deionized water whose purpose was to prepare theaqueous solution for the investigations It is worth notingthat the elements were of analytical grade and were usedwholly without any further refinement or adulteration

22 Preparing Durian Fruit Extracts $e process involvedcollecting and thoroughly rinsing fresh durian fruit indistilled water 25 g was then picked and cut into tiny slicesbefore being smashed and ground in a grinding mixer byadding some 100ml of Millipore water Filtration of the rawextract was done using the Whatman filter paper (no 1)before centrifugation for 10minutes at 8000 rpm to get rid ofimpurities notably fiber Observations made indicated thatfollowing the centrifugation a clear or transparent extractwas obtained and the measure of viscosity was 087mPas$e aqueous solution was stored in a refrigerator to be usedlater

23 Silver Nanoparticles Synthesis For this experiment90ml of 10minus3M of silver nitrate aqueous solution was mixedwith 10ml of the extract $is was followed by adding so-dium hydroxide droplets while stirring to regulate the pH to10 $e mixture was put in a dark room for several hours tosettle $e solution was intermittently subjected to UV-visspectroscopy measurements to gauge how the Ag NPs formAmmonia sensing was then tested by further characterizingthe synthesized silver nanoparticles $ose nanoparticlesthat remained were placed in amber bottles and stored atroom temperature in a dark room

24 Characterizing Synthesized Silver Nanoparticles By us-ing the UV-visible absorption spectrometer specifically theSpecord S100 from Analytica Jena GmbH the optical ab-sorption spectra of these elements can be obtained In thiscase the spectra were collected at room temperature be-tween 350 and 800 nm with an instrument resolution of1 nm $e study of the structure of these Ag nanoparticles is












minus

+ 3H+

(1)



(2)









(a)A

bsor

banc

e (au

)

0min30min60min90min


ndash05

00

05

10

15

20

25

30

35

500 600 700 800400Wavelength (nm)

(b)





200nm

(a)

100nm

(b)

30ndash40

20ndash30

50ndash60

Particle size (nm)

(c)

1 3 5 7 9keV

(d)


(e)

35 45 55 65 752θdeg

111

200

220 311

(f )













500ppm

1000ppm

1500ppm

2000ppm

2500ppm

3000ppmControl

(a)

Abs

orba

nce (

au)

ndash05

00

05

10

15

20

25

30

500 600 700 800400Wavelength (nm)


2000 ppm2500 ppm3000 ppm

(b)

Abs

orba

nce (

au)

00

05

10

15

20

25

30


(c)


2

3

4

5

6

7

8

9

Abs3

91A

bs40

3




5min10min15min20min



ndash01

00

01

02

03

04

05

06

Abso

rban

ce (a

u)


(a)

5min10min15min20min



ndash01

00

01

02

03

04

05

06

Abso

banc

e (au

)

500 600 700 800400Wavelength (nm)

(b)

5min10min15min20min



00

01

02

03

04

05

06

Abso

rban

ce (a

u)

500 600 700 800400Wavelength (nm)

(c)


0

2

4

6

8

10

12

14

16

A39

1A

403

10 20 30 40 50 60 700Time (min)




4 Conclusions



Data Availability


Additional Points




Acknowledgments


References







SNPsNH3

H3N-Ag-NH3






Abs

orba

nce (

au)

ndash05

00

05

10

15

20

25

30

500 600 700 800400Wavelength (nm)

1st m2nd m

3rd m4th m

















































































minus

+ 3H+

(1)



(2)









(a)A

bsor

banc

e (au

)

0min30min60min90min


ndash05

00

05

10

15

20

25

30

35

500 600 700 800400Wavelength (nm)

(b)





200nm

(a)

100nm

(b)

30ndash40

20ndash30

50ndash60

Particle size (nm)

(c)

1 3 5 7 9keV

(d)


(e)

35 45 55 65 752θdeg

111

200

220 311

(f )













500ppm

1000ppm

1500ppm

2000ppm

2500ppm

3000ppmControl

(a)

Abs

orba

nce (

au)

ndash05

00

05

10

15

20

25

30

500 600 700 800400Wavelength (nm)


2000 ppm2500 ppm3000 ppm

(b)

Abs

orba

nce (

au)

00

05

10

15

20

25

30


(c)


2

3

4

5

6

7

8

9

Abs3

91A

bs40

3




5min10min15min20min



ndash01

00

01

02

03

04

05

06

Abso

rban

ce (a

u)


(a)

5min10min15min20min



ndash01

00

01

02

03

04

05

06

Abso

banc

e (au

)

500 600 700 800400Wavelength (nm)

(b)

5min10min15min20min



00

01

02

03

04

05

06

Abso

rban

ce (a

u)

500 600 700 800400Wavelength (nm)

(c)


0

2

4

6

8

10

12

14

16

A39

1A

403

10 20 30 40 50 60 700Time (min)




4 Conclusions



Data Availability


Additional Points




Acknowledgments


References







SNPsNH3

H3N-Ag-NH3






Abs

orba

nce (

au)

ndash05

00

05

10

15

20

25

30

500 600 700 800400Wavelength (nm)

1st m2nd m

3rd m4th m









































































200nm

(a)

100nm

(b)

30ndash40

20ndash30

50ndash60

Particle size (nm)

(c)

1 3 5 7 9keV

(d)


(e)

35 45 55 65 752θdeg

111

200

220 311

(f )













500ppm

1000ppm

1500ppm

2000ppm

2500ppm

3000ppmControl

(a)

Abs

orba

nce (

au)

ndash05

00

05

10

15

20

25

30

500 600 700 800400Wavelength (nm)


2000 ppm2500 ppm3000 ppm

(b)

Abs

orba

nce (

au)

00

05

10

15

20

25

30


(c)


2

3

4

5

6

7

8

9

Abs3

91A

bs40

3




5min10min15min20min



ndash01

00

01

02

03

04

05

06

Abso

rban

ce (a

u)


(a)

5min10min15min20min



ndash01

00

01

02

03

04

05

06

Abso

banc

e (au

)

500 600 700 800400Wavelength (nm)

(b)

5min10min15min20min



00

01

02

03

04

05

06

Abso

rban

ce (a

u)

500 600 700 800400Wavelength (nm)

(c)


0

2

4

6

8

10

12

14

16

A39

1A

403

10 20 30 40 50 60 700Time (min)




4 Conclusions



Data Availability


Additional Points




Acknowledgments


References







SNPsNH3

H3N-Ag-NH3






Abs

orba

nce (

au)

ndash05

00

05

10

15

20

25

30

500 600 700 800400Wavelength (nm)

1st m2nd m

3rd m4th m

















































































500ppm

1000ppm

1500ppm

2000ppm

2500ppm

3000ppmControl

(a)

Abs

orba

nce (

au)

ndash05

00

05

10

15

20

25

30

500 600 700 800400Wavelength (nm)


2000 ppm2500 ppm3000 ppm

(b)

Abs

orba

nce (

au)

00

05

10

15

20

25

30


(c)


2

3

4

5

6

7

8

9

Abs3

91A

bs40

3




5min10min15min20min



ndash01

00

01

02

03

04

05

06

Abso

rban

ce (a

u)


(a)

5min10min15min20min



ndash01

00

01

02

03

04

05

06

Abso

banc

e (au

)

500 600 700 800400Wavelength (nm)

(b)

5min10min15min20min



00

01

02

03

04

05

06

Abso

rban

ce (a

u)

500 600 700 800400Wavelength (nm)

(c)


0

2

4

6

8

10

12

14

16

A39

1A

403

10 20 30 40 50 60 700Time (min)




4 Conclusions



Data Availability


Additional Points




Acknowledgments


References







SNPsNH3

H3N-Ag-NH3






Abs

orba

nce (

au)

ndash05

00

05

10

15

20

25

30

500 600 700 800400Wavelength (nm)

1st m2nd m

3rd m4th m







































































5min10min15min20min



ndash01

00

01

02

03

04

05

06

Abso

rban

ce (a

u)


(a)

5min10min15min20min



ndash01

00

01

02

03

04

05

06

Abso

banc

e (au

)

500 600 700 800400Wavelength (nm)

(b)

5min10min15min20min



00

01

02

03

04

05

06

Abso

rban

ce (a

u)

500 600 700 800400Wavelength (nm)

(c)


0

2

4

6

8

10

12

14

16

A39

1A

403

10 20 30 40 50 60 700Time (min)




4 Conclusions



Data Availability


Additional Points




Acknowledgments


References







SNPsNH3

H3N-Ag-NH3






Abs

orba

nce (

au)

ndash05

00

05

10

15

20

25

30

500 600 700 800400Wavelength (nm)

1st m2nd m

3rd m4th m








































































4 Conclusions



Data Availability


Additional Points




Acknowledgments


References







SNPsNH3

H3N-Ag-NH3






Abs

orba

nce (

au)

ndash05

00

05

10

15

20

25

30

500 600 700 800400Wavelength (nm)

1st m2nd m

3rd m4th m







































































colorimetricdetectionofammoniausingsynthesizedsilver...

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