gold nanoparticle patterning by self-assembly and transfer for lspr based sensing

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GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING T. Ozaki, K. Sugano, T. Tsuchiya, O. Tabata Department of Micro Engineering, Kyoto University , Kyoto, JAPAN ADVISER: Dr .CHENG-SHINE-LIU REPORTER: SRINIVASU V P & HSIEH,HSIN-YI STUDENT ID: 9733881 & 9735803

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GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING. T. Ozaki, K. Sugano, T. Tsuchiya, O. Tabata Department of Micro Engineering, Kyoto University , Kyoto, JAPAN ADVISER: Dr .CHENG-SHINE-LIU REPORTER: SRINIVASU V P & HSIEH,HSIN-YI - PowerPoint PPT Presentation

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Page 1: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

GOLD NANOPARTICLE PATTERNINGBY SELF-ASSEMBLY AND TRANSFER

FOR LSPR BASED SENSINGT. Ozaki, K. Sugano, T. Tsuchiya, O. Tabata

Department of Micro Engineering, Kyoto University

, Kyoto, JAPAN

ADVISER: Dr .CHENG-SHINE-LIUREPORTER: SRINIVASU V P & HSIEH,HSIN-YI

STUDENT ID: 9733881 & 9735803

Page 2: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

OUTLINEAbstractIntroductionProcess overviewTemplate assisted self assemblyResults and discussionTransfer of nanoparticlesLSPR characteristics of assembled

Nanoparticle patternsConclusion

Page 3: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

AbstractPattern formation

Dot and line pattern

Assembled particle pattern transfer

Localized Surface Plasmon Resonance (LSPR)

Page 4: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

Introduction Characteristics of nanoparticles

Conventional nanopatterning techniques

Advantages of proposed method

60-nm diameter gold nanoparticles

Page 5: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

PROCESS OVERVIEW1) Self-assembly step 2)Transfer step

Page 6: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

Template assisted self assemblyMechanism of TASA

Aqueous particle dispersion

Capillary force

Page 7: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

Result and discussionEffect of cross sectional shapeRelation between yield and concentration

The self-assembly yield is defined as the ratio of the total dot-patterned area to the properly assembled area.

Page 8: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

SEM images of each cross-section before resist removal. Shape A, B and Shape C were fabricated by SF6 and CF4 dry etching, respectively.

Page 9: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

Relation between a cross-sectional profile of atemplate pattern and a yield of self-assembly (the concentrationof particle dispersion: 0.002 wt%)

Relation betweenconcentration of particle dispersion and a yield ofself-assembly.

Page 10: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

Capillary force

Page 11: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

Template transfer process

(1) SiO2/Si substrate with assembled particles(2) Uncured PDMS was poured onto the template (base compound : curing agent = 10:1)(3) Degassing for 30 min (4) Curing PDMS (60 for 4 hr)℃(5) Peel off PDMS

Page 12: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

Au self-assemble on the template Transferred pattern on the PDMS(> 90% successful)

Page 13: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

LSPR principle Noble metal nanoparticles exhibit a strong UV-vis absorption

band that is not present in the spectrum of the bulk metal.This absorption band results when the incident photon

frequency is resonant with the collective oscillation of the conduction electrons and is known as the localized surface plasmon resonance (LSPR).

E(λ) = extinction (viz., sum of absorption and scattering) NA = area density of nanoparticles a = radius of the metallic nanosphere em = dielectric constant of the medium surrounding the metallic nanosphere λ = wavelength of the absorbing radiation εi = imaginary portion of the metallic nanoparticle's dielectric function εr = real portion of the metallic nanoparticle's dielectric function χ = 2 for a sphere (aspect ratio of the nanoparticle)

Page 14: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

LSPR characteristicsThese mechanisms are:

resonant Rayleigh scattering from nanoparticle labels in a manner analogous to fluorescent dye labels

nanoparticle aggregationcharge-transfer interactions at nanoparticle surfaces local refractive index changes

• This approach has many advantages including: – a simple fabrication technique that can be performed in most labs– real-time biomolecule detection using UV-vis spectroscopy– a chip-based design that allows for multiplexed analysis

Page 15: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

LSPR applications

Sensoradsorption of small

molecules ligand-receptor bindingprotein adsorption on self-

assembled monolayersantibody-antigen bindingDNA and RNA

hybridizationprotein-DNA interactions

Page 16: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

LSPR scattering spectrum

Schematic of dark-field microscope

Dot pattern

line pattern

aperture

Page 18: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

Scattering spectrums of line patterns w/o polarization

Vacuum air methanol water ethanol hexane toluene xylene

Refractive index 1.0 1.0008 1.329 1.330 1.36 1.3749 1.4963 1.498

line pattern w/o polarization

Page 19: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

Spectrum peak vs. refractive index

Polarizing cube beamsplitter

p-polarized light s-polarized light

Non-polarized light

p-polarized light s-polarized lightnon-polarized light

Page 20: GOLD NANOPARTICLE PATTERNING BY SELF-ASSEMBLY AND TRANSFER FOR LSPR BASED SENSING

ConclusionsSelf-assembly nanoparticle pattern formation

method can be realized more than 90% onto 200 x 200 dots.

Dot and line patterns of gold nanoparticles in diameter of 60 nm were transferred on a flexible PDMS substrate.

LSPR sensitivity will be possible by controlling patterns of the assembled nanoparticles.

In the future, it is expected that this method will realize novel MEMS/NEMS devices with nanoparticles patterns on various 3D microstructures made of various materials via a carrier substrate.