Investigation on an application of silver substrates for sensitive surface plasmon resonance imaging detection

摘要

A surface plasmon resonance (SPR) imaging biosensor based on silver substrates was investigated to demonstratenthat silver could be used as a substrate material for sensitive detection of biomolecular interactions,ndespite its poor chemical stability. The calculation results showed that oxidation of silver film may lead to andecrease in the sensitivity due to a variation in SPR characteristics such as a broader curve width and shallowernminimum reflectance at resonance. The effect of a change in the refractive index of target analytes on thensensitivity was also explored. In particular, it is noteworthy that Ag/Au bimetallic substrates with a thin goldnprotection layer to prevent oxidation of a silver film can provide a significant amplification of SPR imagingnsignals in comparison with conventional gold substrates. © 2010 Optical Society of America