AVS 54th International Symposium
    Plasmonics Topical Conference Tuesday Sessions
       Session PL-TuP

Paper PL-TuP7
Plasmonic Detection of a Model Analyte in Serum by a Gold Nanorod Sensor

Tuesday, October 16, 2007, 6:00 pm, Room 4C

Session: Plasmonics Poster Session
Presenter: S.M. Marinakos, Duke University
Authors: S.M. Marinakos, Duke University
S. Chen, Duke University
A. Chilkoti, Duke University
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We describe the fabrication of a label-free, chip-based biosensor based on the localized surface plasmon resonance (LSPR) of gold nanorods. Gold nanorods were chemisorbed onto a mercaptosilane-modified glass substrate, followed by conjugation of biotin to the nanorods. Streptavidin-binding to biotin was monitored by the wavelength shift of the LSPR peak in the UV-visible extinction spectrum of the immobilized gold nanorods due to the change in local refractive index at the gold nanorod surface induced by streptavidin binding. The limit of detection of the sensor is 94 pM in PBS and 19 nM in serum, and the dynamic range spans 94 pM to 0.19 µM. The advantages of the nanorod-based sensor over a LSPR sensor that we had previously fabricated from gold nanospheres are the significantly lower detection limit and the internal self-reference that the signal of the nanorod sensor provides based on the measurement of peak wavelength shift.