Patent ID: 8363215

Claim:
A method for detecting a target material, comprising: providing a metal surface, the metal being at least one member of Group 11 (IB) of the Periodic Table of the Elements; contacting, in an irradiating chamber, a sample fluid with the metal surface, the sample fluid having a direction of flow, the direction of flow being at a first angle relative to a plane of the metal surface; irradiating the metal surface with radiation to produce scattered radiation, the radiation having an optical path that is at a second angle relative to the plane of the metal surface, the second angle ranging from about 80 to about 90 degrees; determining, by a computer, a reference signal, the reference signal being associated with an intensity of radiation scattered by the metal surface in the substantial absence of analytes and/or the reference signal being associated with an intensity of radiation scattered by a coating previously applied to the metal target being adsorbed on the surface; determining, by a computer, an analyte signal, the analyte signal being associated with an intensity of radiation scattered by analytes located on the metal surface; determining, by a computer for a selected current measurement, a ratio of the reference signal to an analyte signal; and analyzing, by a detector, the scattered radiation for spectral information associated with a target material.