43596815-transducers.doc

8/9/2019 43596815-Transducers.doc

1/69

Transducers in Biosensors I(Week 4)

[email protected]

Centre for NanoBioengineering & Spintronics,

Chungnam National University,Daejeon,Korea
mailto:[email protected]:[email protected]


2/69

Transducers in Biosensors I

Various types of transducers !rinciples andapplications

" !otentiometric#amperometricconductrometric#resistormetric

" $ptical

Calorimetric

%iscellaneous

10/5/2009 WCU Project,CNU,[email protected] 2


3/69

1. Brief over view of Transducers

Transducer a device that converts one form of

energy to another nergy forms as input and output

' Thermal temperature, heat, heat flo(,)))

' Mechanical position, velocity, acceleration,

force, pressure, )))' Chemical concentration, composition, reaction

rate*

' Opical intensity, (avelength, phase, polari+ation

' Ma!neic field intensity, flu, magneti+ation, etc)' "lecrical voltage, current, charge, *

an! meas"ring an# sensing #e$ices, as %ell as lo"#s&ea'ers, thermoco"&les, micro&hones, an# &honogra&h&ic'"&s, ma! be terme# trans#"cers.

10/5/2009 WCU Project, CNU,[email protected] (


4/69

Transducer

-U!.C Definition " /ransduction of the 0iosensor signal is a process

that is concurrent,and (ithin the specialenvironment of the 0iosensing element)

" /he transduction efficiency determines many ofthe analytical characteristics of the 0iosensors,

such as the signal sta0ility, reproduci0ility,detection limit, and in many cases the operationalsta0ility and selectivity)


5/69

Transducers in #iosensors

)he trans#"cer con$erts the biochemical interactions intomeas"rable electronic signals. *lectrochemical, electro+o&tical, aco"stical, an# mechanical trans#"cers are among

the man! t!&es "se# in biosensors. )he trans#"cer %or'seither #irectl! or in#irectl!.

l0/5/2009 #$ances in -iosensors, -.. alhotra . P. . )"rner 5WCU Pro ect CNU bansi.malhotra mail.com

asool!et al, -iosensors , (, l 320054
mailto:[email protected]:[email protected]:[email protected]


6/69

10/5/2009 WCU Project,CNU,[email protected]


7/69

$esponsivi% and &eecivi%

es&onsi$it! 6 7"t&"t signal / 8n&"t signal

3 )rans#"cing ecienc! : i signals ha$e same "nits 4

etecti$it! 6 ;ignal/Noise o o"t&"t signal/si


8/69

'ensorand (cuaor

Sensor and actuator are 1inds of transducers Sensors

%agnify#Demagnify an environmental pertur0ation2signal#noise3 and transform into an o0serva0leenergy form

.ctuators

Use small controlled energy to cause an

o0serva0le 2or controlla0le3 pertur0ation2movement#energy radiation3 to the environment

10/5/2009 WCU Project,CNU,[email protected] =


9/69

)rans#"cers *>am&les

*n

*lectrochemical1.m&erometric

P2o

.tentiometric

(c.Con#"ctometr

i

Cs!

lsatre'm

os>!gen electro#e, me#iate#

electro#e iel##oe>eelecct

ttrroa#nesiss,tioorns,sleiglehcttia$#e#ereles

csa

trb

ol#ees,

7&tical Po&htoic

toa#l

isoe#n

es,o%

rsa$eg"i#e &A en

le,ctric cr!stals, s"race Bolatile gases an#$a&ors, antibo#ies

Calorimetric10/5/2009

)hermistor or thermo&ile

T%pes of Transducers commonl%used in #iosensors

*n


10/69

1. "lecrochemical sensorPrinciple: *lectrochemical reactions ta'e &lace at electro#e+

electrol!te interaces an# &ro$i#e a s%itch or electricit! to lo% bet%eent%o &hases o #ierent con#"cti$it!, i.e. the electro#e 3electrons or holesare the charge carriers4 an# soli# or li"i# electrol!te 3ions are the maincharge carriers4

)here are three t!&es:

14 Potentiometric 24 m&erometric an# (4 Con#"ctometric. e.g 7>i#ation o e3CN4

10/5/2009 WCU Project,CNU,[email protected]#$ances in -iosensors, -.. alhotra . P. .

)"rne


11/69

1. M"$OM"T$IC BIO'"*'O$'

" Wih amperomeric sensors+ he elecrodepoenial is mainained a a consan levelsufficien for o,idaion or reducion of he

species of ineres (or a su#sanceelecrochemicall% coupled o i).

" The curren ha flows is proporional ohe anal%e concenraion.

Id - n.(&sCId



12/69

M"$OM"T$IC BIO'"*'O$'

" mperomeric en/%me elecrodes #asedon o,idases in com#inaion wih h%dro!enpero,ide indicain! elecrodes have

#ecome mos common amon! #iosensors.

" Wih hese reacions+ he consumpion ofo,%!en or he producion of h%dro!enpero,ide ma% #e moniored.

" The firs #iosensor developed was #asedon he use of an o,%!en elecrode.



13/69

T%pical &esi!n

Working Electrode

(e.g. Pt, Au, C)

Auxiliary Electrode(e.g. Pt wire)

Reference Electrode(e.g. Ag/AgCl, SCE)

e flow

Stirbar

uffer !olution

(e.g. "ri!, #PS, Citrate)

incor$orating electrolyte

(e.g. %Cl, &aCl)10/5/2009 WCU Project,CNU,[email protected] 1(
mailto:[email protected]:[email protected]:[email protected]


14/69

0lucose

'luco!e *

",ample

O,idase 'luconic Acid +**

"e $roduct, +**, i! oxidi!ed at -01 2! a

Ag/AgCl reference electrode.

"u!, a $otential of -01 i! a$$lied andte oxidation of +** 0ea!ured. "i! current

i! directly $ro$ortional to te concentration

of gluco!e.

10/5/2009 WCU Project, CNU,[email protected] 1D


15/69

/ypical curve

T%pical 'pecra

3 (nA)

4

4

l08582009

4 4 *

f'luco!e5, 06 l5


16/69

Clark xygen Electrode

-

+

Electrode body

KCl soln.Silver anode

Polyethylene membrane

Platinum cathode

101512009 WCU Project,CNU,[email protected] 1


17/69


" /he dra(0ac1 of oygen sensors is that they arevery prone to interferences from eogenousoygen)

" 4565 is more commonly monitored) -t is oidisedat 789$mV vs) a .g#.gCl reference electrode)

" .t the applied potential of anodic 4565 oidation,ho(ever, various organic compounds 2e)g)ascor0ic acid, uric acid, glutathione,acetaminophen )))3 are co:oidised)

101512009 1


18/69


" Various approaches have 0een ta1en toincrease the selectivity of the detectingelectrode 0y chemically modifying it 0y theuse of

' %em0ranes

' %ediators

' %etallised electrodes

' !olymers

101512009 WCU Project,CNU,[email protected] 1=


19/69


1. Mem#ranes.

arious permselecive mem#ranes have #een

developed which conrolled species reachin! he

elecrode on he #asis of char!e and si/e.

",amples include cellulose aceae (char!e and si/e)+

*afion (char!e) and pol%car#onae (si/e).

The disadvana!e of usin! mem#ranes is+ however+

heir effec on diffusion.



20/69


2. Mediaors

Man% o,idase en/%mes can uilise arificial elecron

accepor molecules+ called mediaors.

mediaor is a low molecular wei!h redo, couple

which can ransfer elecrons from he acive sie ofhe en/%me o he surface of he elecrode+ here#%

esa#lishin! elecrical conac #eween he wo.

These mediaors have a wide ran!e of srucures and

hence properies+ includin! a ran!e of redo, poenials.



21/69

M"$OM"T$IC BIO'"*'O$'+

C of eC*



22/69


" amples of commonly used mediators are

' ;errocene 2insolu0le3

' ;errocene dicar0oylic acid 2solu0le3' Dichloro:indophenol 2DC-!3

' /etramethylphenylenediamine 2/%!D3

' ;erricyanide

'


23/69

M"$OM"T$IC BIO'"*'O$'3. Meallised elecrodes

/he purpose of using metallised electrodes is to create

conditions in (hich the oidation of en+ymatically

generated 4565 can 0e achieved at a lo(er applied

potential, 0y creating a highly catalytic surface)

-n addition to reducing the effect of interferents, due

to the lo(er applied potential, the signal:to:noise

ratio incresaes due to an increased electrochemically

active area)

101512009 WCU Project,CNU,[email protected] 2(


24/69


25/69


26/69

M"$OM"T$IC BIO'"*'O$'4. ol%mers

s wih mem#ranes+ pol%mers are used o preven

inerferin! species from reachin! he elecrode

surface. ol%mers differeniae on he #asis of si/e

and char!e.

n e,ample is ha of pol%p%rrole. pol%p%rrole

film has o #e in he reduced sae o #ecomepermea#le for anions. If he film is o,idised+ no

anion can permeae.



27/69


" ",amples of commonl% usedpol%mers are5

' ol%p%rrole

'

ol%hiophene' ol%aniline

' &iamino#en/ene

' ol%phenol

101512009WCU Project,CNU,[email protected] 2


28/69

1.1 mperomeric ransducionm&erometr! encom&asses a gro"& o electroanal!tical

techni"es. it monitors the c"rrent generate# at a i>e#bias &otential.

Einear relation bet%een the concentration o the anal!tean# the c"rrent generate# is obtaine#.

;e$eral techni"es li'e c!clic $oltammeter!, lo%injection anal!sis st"#ies, etc. are commonl! em&lo!e#.

ost biosensors are base# on am&erometric+t!&e#etection.

m&erometric biosensors ha$e been at the oc"s o electroanal!ticalresearch since the irst re&ort o the en


29/69

Clark%pe o,%!en elecrode

*>am&le o m&erometricsensor

101512009

Clar' an# E!ons 192

WCU Project,CNU,[email protected]


30/69

1.2 oeniomeric ransducion

&otentiometric biosensor monitorsthe &otential "n#er


31/69

OT"*TIOM"T$IC BIO'"*'O$'

" In poeniomeric sensors+ he /erocurren poenial

(relaive o a reference)developed a a selecive mem#rane orelecrode surface in conac wih a samplesoluion is relaed o anal%e

concenraion." The main use of poeniomeric

ransducers in #iosensors is as a p6elecrode.

101512009 WCU Project,CNU,[email protected] (1


32/69


" " - "o 7 $TIn 3n8anal%e9

' "o is a consan for he s%sem

' $ is he universal !as consan

' T is he a#solue emperaure

' / is he char!e num#er

' is he arada% num#er

' 3n8anal%e9 is he naural lo!arihm of heanal%e acivi%.



33/69

4

OT"*TIOM"T$ICBIO'"*'O$'

" The #es known poeniomeric sensor ishe Ion 'elecive "lecrode (I'").

" 'olven pol%meric mem#rane elecrodesare commerciall% availa#le and rouinel%

used for he selecive deecion of severalions such as :

7+ *a

7+ Ca

27+ *6

7+ 6

7+ CO

2)4 3

in comple, #iolo!ical marices.

" The ani#ioics nonacin and valinom%cinserve as neural carriers for hedeerminaion of *6

7and :

7+ respecivel%

.

101512009 WCU Project,CNU,[email protected] ((


34/69

T%pical Cell

$g%$gCl reerence electrode

&nternal a'ueous

illing solution

(i'uid ion exchanger

Membrane%salt bridge

l0l5l2009

Porous membrane containing iono!hore(D


35/69

OT"*TIOM"T$ICBIO'"*'O$'

" -Ss used in conjunction (ith immo0ili+eden+ymes can serve as the 0asis of electrodesthat are selective for specific en+ymesu0strates)

" /he t(o main ones are for urea andcreatinine)

" /hese potentiometric en+yme electrodes areproduced 0y entrapment of the en+ymes

urease and creatinase, on the surface of a7cation sensitive 2N4= 3 -S)



36/69

5 = >

=


Urea 7 4 6 7 47 urease 5N4 7 7 4C6 :

Creatinine 7 456creatininase

N:methylhydantoin 7 N47

!enicillinpenicillinase

!enicillonic.cid

-n contact (ith p4 electrode)

101512009 WCU Project,CNU,[email protected] (


37/69

1.3 Conducomeric ransducionCon#"cti$it! is a meas"rement o the abilit! o a sol"tion to

con#"ct anelectric c"rrent. instr"ments meas"re con#"cti$it! b! &lacingt%o &lates o con#"cti$e material %ith 'no%n area an# #istancea&art in a sam&le. )hen a $oltage &otential is a&&lie# an# theres"lting c"rrent is meas"re#. Using 7hms la%

)his is a techni"e %here the changesin ionic concentrations are meas"re#. i the biocatal!st&ro#"cesionic &ro#"cts, or cons"mes ions, an# the s"&&ortsol"tion haslo% electrical con#"cti$it!, this is oten acon$enient an# sim&letechni"e.

101512009 WCU Project,CNU,[email protected] (


38/69

resen saus of elecrochemical #iosensors

101512009 WCU Project,CNU,[email protected] (=

'ome elecrochemical #iosensors ford i d i i f l


39/69

deecion and esimaion of anal%es

101512009 WCU (9

Project,CNU,[email protected]


40/69

2. Opical Transducers

Princi&le: 7&tical sensors rel! on the o&tical trans#"ctiono the signal an# com&rise "ltra$iolet, $isible an# inrare#s&ectro&hotometr! in transmission or relectance mo#es.

)he relationshi& bet%een the inci#ent light intensit! an#thetransmitte# ra#iation is gi$en b! the Eambert+-eer la%

101512009 WCU Project,CNU,[email protected] D0

Opical Transducers


41/69

Opical Transducers

7&tical metho#s

ha$e been "se# classicall! to

monitoranal!te concentrations. Pro&erties li'e absor&tion, reracti$ein#ices, l"orescence, &hos&horescence,chemil"minescence, etc., can be "se# in or#erto monitor

the biological recognition in biosensors. )he #e$ices can beminiat"ri


42/69

",amples of Opical Transducers

" 7&tical ibers" ;"race &lasmon resonance sensors 3;P4" Wa$eg"i#e base# ;P" integrate# intererometers 3ach+Fehn#er an#

Go"ng intererometers4

" ierential mo#e intererometr!" esonant mirror" ?rating co"&ler" -i#iracti$e co"&lers

" 7&tical %a$eg"i#e lightmo#e s&ectrosco&! s!stem37WE;4

" elactometric intererence s&ectrosco&! 31i9;4



43/69

OTIC; BIO'"*'O$'

" The area of #iosensors usin! opical deecionhas developed over he las num#er of %ears.

" The #asis of hese s%sems is ha en/%maicreacions aler he opical properies of some

su#sances allow hem o emi li!h uponilluminaion.

" Means of opical deecion include fluorescence+phosphorescence+ chemil#ioluminescence...

101512009 WCU Project,CNU,[email protected] D(


44/69

OTIC; BIO'"*'O$'" dvana!es of opical #iosensors include

8 due o fi#re opics+ miniaurisaion is possi#le

8 in !itu measuremens are possi#le

8 in 2i2o measuremens are possi#le

8 diode arra%s allow for mulianal%e deecion

8 si!nal is no prone o elecroma!neicinerference

" &isadvana!es include5

8

am#ien li!h is a sron! inerferen8 fi#res are ver% e,pensive

8 indicaor phases ma% #e washed ou wih ime

101512009 WCU Project,CNU,[email protected] DD


45/69

OTIC; BIO'"*'O$'

" i#re opics are a su#class of opicalwave!uides which operae usin! heprinciple of oal inernal reflecion.

" ;i!h inciden on he inerface #eweenwo dielecric media is eiher refleced orrefraced accordin! o 'nell


46/69

Workin! of '$The SPR is an optical phenomenon due to a charge density oscillation atthe interface of a metal and a dielectric, which have dielectric constants of

opposite signs

101512009 WCU D

Project,CNU,[email protected]

'urface lasmon $esonance


47/69

2i3 Design prisms coated (ith a thin film of metal, usuallygold or silver 2'99:nm thic13, typically 1no(n as the Kretschmann

configuration?0y prism coupling @or1ing a light (ave passesthrough a high:refractive:inde prism and is totally reflected at the

prism metal layer?

2ii3Design(aveguide coupled (ith a thin film of metal?@or1ing 0y optical (aveguide the light (ave is guided 0y anoptical (aveguide and, (hen entering the region (ith a thin metal

layer, it evanescently penetrates through the metal layer eciting an

S!< at its outer 0oundary?

2iii3 Designmetalli+ed diffraction gratings (here the metalthic1ness can 0e much greater 2up to A96: nm thic13

@or1ing 0y light diffraction on a diffraction grating thecomponent of the (ave vector of the diffracted (aves parallel to the

interface is diffraction:increased 0y an amount that is inversely

prol0plo5lr2t0io09nalto the period of the grating and cWaCnU0e matched to that of D

an S!


48/69

T%pical si!nal verses ime curve

101512009 WCU Project,CNU,[email protected] i;-N: (+5D0+

DD0===


49/69

D 0 ==

+

T%pical $esponse Curve


50/69

T%pical $esponse Curve


O er ie of opical #iosensors


51/69

Overview of opical #iosensors


Comparison of sensiiviies fordiff i l #i


52/69

differen opical#iosensors

S!< has 0een one of the leading transducer techniues due to its etremely high sensitivity,

offering detection limits up to fe( ppt 2pg mC'A 3


Baceriorhodopsin5Biophoonic Maerial


53/69

Nat"ral )rans#"cer: Con$erts light into chemical energ!

l0l5l2009 52

rtiicial etina

4. Calorimeric


54/69

Principle8Calorimetricsensors are base# on meas"rement o the heat

&ro#"ce# b!8themolec"lar recognition reaction an# the amo"nt o heat&ro#"ce# is cor+8relate#to the reactant concentration. Calorimetr! can be"se# or #irect meas"rment o heat changes associate# %iththermochemical &roceses 3 ?rime, 19=54.8 )he metabolic acti$it! o the biocom&onent ca"sesan increase in tem&erat"re, %hich is transorme# into a#etectable electrical signal.

" "n/%mecaal%sed reacions e,hi#i hesame enhalp% chan!es as sponaneouschemical reacions.

" Considera#le hea evoluion is noed (=IOOk>Imol).

" Thus+ calorimeric ransducers are5(

universall% applica#le in en/%me sensors.

C l i i T d


55/69

Calorimeric Transducers

" The hermal #iosensors consruced have#een #ased on5

8

direc aachmen of he immo#ilised en/%me orcell o a hermisor

8 Immo#ilisaion of he en/%me in a column inwhich he hermisor has #een em#edded.

T - n,6Icp

101512009 WCU Project,CNU,[email protected] 5D

T%pical alues of enhalp%


56/69

7acticdeydrogena!e Pyru2ate -*.4

H 8 7acta0a!e Penicillin ' -9.

:rea!e :rea -.-

:rica!e9

:ric acid =)A

T%pical alues of enhalp%

n+yme Su0strate 8I 3k;30ol)

Catalase 4ydrogen peroide A66)=

Cole!teroloxida!e Cole!terol *.

43596815-transducers.doc

Documents