AVS 49th International Symposium
    Biomaterials Thursday Sessions
       Session BI+HS+SS-ThM

Paper BI+HS+SS-ThM5
A Gold Nanoparticle Sensor to Interrogate Biomolecular Interactions in Real-time on a Surface

Thursday, November 7, 2002, 9:40 am, Room C-201

Session: Biosensors and Biodiagnostics
Presenter: A. Chilkoti, Duke University
Authors: N. Nath, Duke University
A. Chilkoti, Duke University
Correspondent: Click to Email
We present a label-free optical technique to study biomolecular interactions in real time on a surface that is based on particle surface plasmon resonance (PSPR). We demonstrate that the absorbance spectrum of immobilized gold nanoparticles on glass exhibits a red shift as well as an increase in the absorbance at peak wavelength as a function of binding of biomolecules at the solid-water interface. The results obtained with the absorbance sensor were compared with those obtained using conventional SPR for fibrinogen adsorption onto a COOH-terminated surface and for the binding of streptavidin to a biotin-functionalized surface. We have also examined the sensitivity and dynamic range of the sensor as a function of nanoparticle size, and found a threefold improvement in sensitivity as the size of the nanoparticles is increased from 13 to 50 nm. This sensor is attractive because of its simplicity: gold nanoparticles are easily prepared with high reproducibility, they can be readily immobilized on glass, and their absorbance spectrum can be easily measured using widely available UV-vis spectrophotometers. Furthermore, this technique should be easily amenable to the design of chips in an array format for application in high-throughput immunoassays and proteomics.