A surface plasmon resonance (SPR) imaging biosensor based on silver substrates was investigated to demonstrate that silver could be used as a substrate material for sensitive detection of biomolecular interactions, despite its poor chemical stability. The calculation results showed that oxidation of silver film may lead to a decrease in the sensitivity due to a variation in SPR characteristics such as a broader curve width and shallower minimum reflectance at resonance. The effect of a change in the refractive index of target analytes on the sensitivity was also explored. In particular, it is noteworthy that Ag/Au bimetallic substrates with a thin gold protection layer to prevent oxidation of a silver film can provide a significant amplification of SPR imaging signals in comparison with conventional gold substrates.
© 2010 Optical Society of America
Original Manuscript: April 8, 2010
Revised Manuscript: July 22, 2010
Manuscript Accepted: August 20, 2010
Published: September 22, 2010
Vol. 5, Iss. 14 Virtual Journal for Biomedical Optics
Seung Ho Choi and Kyung Min Byun, "Investigation on an application of silver substrates for sensitive surface plasmon resonance imaging detection," J. Opt. Soc. Am. A 27, 2229-2236 (2010)