The nanoparticle-plasmon resonance for proteomics Bongsu, Jung Jaehun, Seol Final Project, ME381R December 2,2004

Table of contents Proteomics Motivation Particle surface plasmon resonance Fabrication method for nanostructure –Nanosphere lithography –Ultraflat nanosphere lithography

Proteomics Completing DNA map is not sufficient to elucidate biological function DNA or mRNA can’t encode the arrangement for cell signal pathway or a metabolic cascade Poor correlation between protein and mRNA Post-transcriptional regulation of gene expression problem

Motivation :Why Surface Plasmon Resonance ? (as non-labeling method) Current fluorescent labeling technique for proteomics is complicate and labor intensive job Fluorescent labeling method gives interference and photobleaching to data SPR is real-time, very sensitive, easy to use non- labeling technique for proteomics

Metal Nanoparticles as Sensors Localized SPR: localized: Localized oscillation of an electron density wave -Probing only a very thin layer around each particle -Each particle acts as its own sensor -High field enhancements at edges -Very easy detection (UV-Vis) Problems with localized SPR: Size and shape have strong influence on the resonance Shape difficult to control above 40 nm diameter Non-spherical particles difficult to preserve Stationary depolarization Dynamic depolarization from phase difference on larger particle Radiation damping correction

Dipole vs quadrupole resonance J. Phys. Chem. B 2003, 107, Dipole and quadrupole resonance is controlled by size of spheres J. Phys. Chem. B 2003, 107,

Particle shape dependent LSPR JOURNAL OF CHEMICAL PHYSICS VOLUME 116, NUMBER 15, 2002,

Strong field enhancement in non-spherical shape Journal of cluster science Vol. 10, No , DDA simulated electric field contours with for various shapes. (a) The innermost contour represents the grid boundaries of a 30nm sphere. The drop in intensity is from 50 to 1. (b) 2:1 spheroid has high field intensity to the high curvature periphery of the particle. The drop in intensity is from 125 to 1. (c) The truncated tetrahedron has high field intensity near the tip. The drop in intensity is from 500 to 1. (a)(b)(c) Huge field enhancement at tip of triangle shape when compared to spherical shape

Linear response to environmental changes J. Am. Chem. Soc. 2001, 123,

Fabrication technique : Nanosphere Lithography Spin-coating technique Slow vertical withdrawal of a substrate technique Tilting a substrate technique Horizontal movement of a substrate Depositing method :

Fabrication technique : Nanosphere Lithography Slow vertical withdrawal method Appl. Phys. Lett., Vol. 77, No. 17, 23 October 2000

Fabrication technique : Nanosphere Lithography Horizontal movement method H, height of meniscus R, Humidity ratio T, temperature C, Concentration ratio of liquid W, Width of cuvette Speed of horizontal movement S, Shape of meniscus Substrate, glass

Fabrication technique : Nanosphere Lithography Main principles for producing monolayer Capillary force (Surface tension )due to meniscus formation Convective flow due to water evaporation Particle convective flow Water convective flow Water evaporation Surface tension

Fabrication technique : Nanosphere Lithography Monolayer masking principle for periodic pattern of nanostructure J. Vac. Sci. Technol. A, Vol. 13, No. 3, May/Jun 1995 J. Phys. Chem. B, Vol. 103, No. 19, 1999

Frey, W., Woods, C. K., Chilkoti, A.: Adv. Mat. 12 (20), 1515 (2000) Sphere deposition 2Metal M 1 evaporation 3Sphere removal 4Metal M 2 evaporation 5Low viscosity epoxy 6Mechanical support 7Dry lift-off Fabrication technique : Ultraflat Nanosphere Lithography

Advantages of UNSL Sharp corner and edges are well preserved Only one side is exposed to surface Various choices of substrate J. Phys. Chem. B 2000, 104, Conventional NSL UNSL Adv. Mater. 2000, 12, No. 20, October 16

Future applications Surface functionalization for proteomics or cancer detection Protein spotting glass Gold SiO 2 Target protein light Measuring & monitoring binding affinity, enzyme reaction or antibody