AVS 52nd International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP37
Combinatorial Characterization of Geometric Effects on the Optical Properties of Gold Nanostructures for Biosensors Optimization

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Biomaterial Interfaces Poster Session
Presenter: G. Nusz, Duke University
Authors: G. Nusz, Duke University
A. Curry, Duke University
A. Wax, Duke University
A. Chilkoti, Duke University
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Optimizing the performance of nanoparticle optical biosensors requires design of nanostructures that exhibit the greatest change in their extinction spectrum upon receptor-analyte binding. Previous studies have suggested that highly anisotropic nanostructures that exhibit geometric asperities are likely to provide enhanced sensitivity compared to isotropic particles. Unfortunately, the optical sensitivities for nanostructures with complex shapes must be determined experimentally because current theoretical modeling and computer simulation methods for complex geometries are computationally intensive and time-consuming. Thus, a combinatorial experimental approach that allows the rapid and high-throughput optical characterization of many structures of different size and shapes is desirable to rapidly optimize the design of such nanobiosensors. As proof-of-principle of this high-throughput optimization approach, arrays of nanostructures with varying geometries with minimal dimensions of 60 nm were fabricated on glass substrates by electron beam lithography. Scattering spectra were collected with a grating spectrometer simultaneously from several nanostructure configurations on a customized Zeiss Axiovert 200 under darkfield illumination. The characterization of the geometric dependence of the optical properties of the gold nanostructures could be experimentally determined in single snapshot mode at the individual nanoparticle level using this set-up. Studies on the optical sensitivity of these nanostructures in response to perturbation of their local refractive index are currently in progress.