Patent ID: 7351588

Claim:
An optical sensor for use with a visible-light laser excitation beam, and a Raman spectroscopy detector, for detecting the presence chemical groups in an analyte applied to the sensor, comprising (a) a substrate; (b) a plasmon resonance mirror formed on a sensor surface of the substrate; (c) disposed over said mirror, a plasmon resonance layer composed of a periodic array of plasmon resonance particles having (i) a coating effective to binding analyte molecules, (ii) substantially uniform particle sizes and shapes in a selected size range between 50-200 nm (ii) a regular periodic particle-to-particle spacing that is less than 700 nm, and (d) an optically transparent dielectric layer having a selected thickness in the thickness range between 2-40 nm separating said mirror from said particle layer; wherein irradiation of analyte bound to said particle layer with said laser excitation beam is effective to produce in said detector, a Raman spectrum of said analyte that with an amplification factor of at least 10 10 .