Patent ID: 6770190
Filing Date: 2004-08-03
Classification: G01N

Abstract:
A method of electrochemical detection of an analyte in a sample, which method comprises the steps of:(a) providing a sensing electrode having an electroconductive polymer coating, the coating having immobilised therein or adsorbed thereto receptors which are capable of binding the desired analyte to be detected in the sample; (b) contacting the sensing electrode with a test solution comprising the sample so that the desired analyte to be detected in the sample binds to said immobilised or adsorbed receptors; (c) contacting the sensing electrode with a solution comprising secondary receptors capable of binding to said analyte at a site spatially distinct from the site of binding to the immobilised or adsorbed receptors, said secondary receptors being conjugated with a charge label; (d) monitoring the electric potential difference between the sensing electrode of part (c) and a reference electrode when both are immersed in an electrolyte; and (e) monitoring the electric potential difference between the sensing electrode of part (d) and a reference electrode following a change in the ionic strength of the electrolyte at constant pH.