Optical detection device chemistry pyroelectric transducer or piezoelectric

A device for performing an assay for an analyte in a sample comprising: a radiation source adapted to generate a series of pulses of electromagnetic radiation; a transducer having a pyroelectric or piezoelectric element and electrodes which are capable of transducing energy generated by non-radiative decay into an electrical signal; a detector that is capable of detecting the electrical signal generated by the transducer; a first next to the transducer reagent, the first reagent having a binding site which is capable of binding a labeling reagent in proportion to the concentration of analyte in the sample, the labeling reagent is capable of absorbing the electromagnetic radiation generated by the source radiation to generate energy by non-radiative decay; a second reagent next to the transducer, the second reagent having a lower affinity for the labeled reagent under the test conditions, the first reagent; and a third near the transducer reagent, the third reagent having a binding site which is capable of binding the labeling agent, wherein the third reagent has affinity labeling reagent that is less influenced than the first reagent concentration analyte or the complex or derivative of the analyte.