Device for detecting an analyte

Abstract

This invention relates to a device for detecting 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 is capable of transducing energy generated by non-radiative decay into an electrical signal; a detector which is capable of detecting the electrical signal generated by the transducer; a first reagent proximal to the transducer, the first reagent having a binding site which is capable of binding a labelled reagent proportionally to the concentration of the analyte in the sample, which labelled reagent being capable of absorbing the electromagnetic radiation generated by the radiation source to generate energy by non-radiative decay; a second reagent proximal to the transducer, the second reagent having a lower affinity for the labelled reagent under the conditions of the assay than the first reagent; and a third reagent proximal to the transducer, the third reagent having a binding site which is capable of binding the labelled reagent, wherein the third reagent has an affinity for the labelled reagent which is less influenced than the first reagent by the concentration of the analyte or the complex or derivative of the analyte.

What is claimed is: 
     
         1 . A method for detecting an analyte, or a complex or derivative of the analyte, in a sample comprising:
 exposing the sample to a device, wherein said device comprises;   a radiation source adapted to generate a series of pulses of electromagnetic radiation;   a transducer having a pyroelectric or piezoelectric element and electrodes which is capable of transducing energy generated by non-radiative decay into an electrical signal;   a detector which is capable of detecting the electrical signal generated by the transducer;   a first reagent proximal to the transducer, the first reagent having a binding site which is capable of binding a labelled reagent proportionally to the concentration of the analyte in the sample, which labelled reagent being capable of absorbing the electromagnetic radiation generated by the radiation source to generate energy by non-radiative decay;   a second reagent proximal to the transducer, the second reagent having a lower affinity for the labelled reagent under the conditions of the assay than the first reagent;   a third reagent proximal to the transducer, the third reagent having a binding site which is capable of binding the labelled reagent, wherein the third reagent has an affinity for the labelled reagent which is less influenced than the first reagent by the concentration of the analyte or the complex or derivative of the analyte; and   transducing the energy generated into an electrical signal and detecting the signal.   
     
     
         2 . A method as claimed in  claim 1 , wherein the method is carried out without removing the sample from the transducer between the steps of exposing the sample to the transducer and transducing the energy generated into an electrical signal. 
     
     
         3 . A labelled reagent comprising a label capable of absorbing electromagnetic radiation to generate energy by non-radiative decay, a carrier attached to the label, and attached to the carrier, a first member of a first complementary binding pair and a first member of a second complementary binding pair. 
     
     
         4 . A labelled reagent as claimed in  claim 3 , wherein the first member of the first complementary binding pair is selected from therapeutic drugs, drugs of abuse, vitamins and hormones, and the first member of the second complementary binding is selected from BODIPY FL, Dansyl, AlexaFiuor 405, AlexaFiuor 488, Lucifer Yellow, Rhodamine, Texas Red, biotin and dinitrophenyl aminohexanoic acid.