AVS 53rd International Symposium
    Biomaterial Interfaces Tuesday Sessions
       Session BI2-TuM

Paper BI2-TuM13
Towards a Label-Free Biosensor: Defining and Measuring Sensitivity of Nanoscale Plasmonic Systems

Tuesday, November 14, 2006, 12:00 pm, Room 2014

Session: Biodiagnostic Innovation
Presenter: G. Nusz, Duke University
Authors: G. Nusz, Duke University
A. Curry, Duke University
A. Wax, Duke University
A. Chilkoti, Duke University
Correspondent: Click to Email
A label-free biosensor based on the optical response of the surface plasmon resonance of nanostructures (nanoSPR) is proposed. This system transduces nanoscopic changes in refractive index near the nanostructure surfaces into a macroscopically measureable signal. The sensor is designed such that binding of the target biomolecule to the metal nanostructure effects this refractive index change, generating the signal. Here, we present our work on optimizing the nanostructures to create the most useful biosensing system. We examine possible routes towards optimizing sensor sensitivity with an emphasis towards design considerations such as nanostructure synthesis, detection method, analyte structure and system applicability to biological samples. Specifically, we present our analysis of single-nanoparticle spectroscopy of both chemically synthesized and electron beam lithographically fabricated arrays of single and near-field coupled structures. We define and analyze sensitivity of nanostructures in terms of refractive index sensitivity, electric field enhancement and model binding studies. With these assays, it is possible to form a more complete characterization of nanoparticles in general and to determine of optimal nanoparticle characteristics for biosensors.