Patent ID: 7429357

Claim:
A method of detecting the presence of a target analyte in a sample environment utilizing a reagent deposit reactive to exposure to the target analyte and said reagent deposit further characterized by a capacity to absorb electromagnetic energy irradiated thereupon, wherein an absorption capacity of the reagent deposit changes after exposure to the target analyte, said method comprising the steps of: providing a transparent substrate having a first surface, a second surface disposed opposite the first surface, and a reagent deposit supported on one of either the first or second surfaces; positioning an electromagnetic energy emitting source (EM source) relative to the transparent substrate such that the second surface is positioned intermediate the first surface and the EM source; positioning a pyroelectric transducer for detecting energy absorbed by the reagent deposit adjacent the reagent deposit; directing a sample environment past the reagent deposit, thereby initiating a reaction between the reagent deposit and any target analyte in the sample environment; operating the EM source to irradiate the reagent deposit by way of a path directed through the transparent substrate; and, utilizing the pyroelectric transducer to detect the energy absorbed by the reagent deposit upon irradiation by the EM source and generate output signals corresponding with a measure of the detected energy, such that the output signal corresponds with the degree of exposure of the target analyte to the reagent deposit; wherein the reagent deposit is spaced apart from the pyroelectric transducer.