Patent ID: 7989211

Claim:
A method for determining the presence or amount of perchlorate and nitrate in a test sample comprising: providing a test sample having an amount of perchlorate and including nitrate; adding a SERS reagent to said test sample, wherein said SERS reagent comprises: a metal nanoparticle having a surface; and a functional group, wherein said surface of said nanoparticle is modified by said wherein said surface is modified by said functional group, and wherein said functional group provides a positive charge to said surface; allowing said SERS reagent to bind to said perchlorate; measuring the intensity of the Raman scattering signal; determining the presence or amount of said perchlorate; allowing said SERS reagent to bind to said nitrate; measuring the intensity of the Raman scattering signal; and determining the presence or amount of said nitrate.