Method for specifically detecting a test substance using photocurrent

摘要

A method, an electrode, a measuring cell, and a measuring device are disclosed which can detect and quantitatively determine an analyte having specific bonding properties, in a highly sensitive, simple and accurate manner using photocurrent. This method comprises contacting a working electrode and a counter electrode with an electrolyte medium, wherein the working electrode has an analyte immobilized thereon through a probe substance and wherein the analyte is bonded to a sensitizing dye; irradiating the working electrode with light to photoexcite the sensitizing dye; and detecting photocurrent flowing between the working electrode and the counter electrode, wherein the photocurrent is generated by transfer of electrons from the photoexcited sensitizing dye to the working electrode. The working electrode comprises an electron accepting layer comprising an electron accepting substance capable of accepting electrons released from the sensitizing dye in response to photoexcitation, wherein the probe substance is supported on a surface of the electron accepting layer. The electron accepting substance is an oxide semiconductor having an energy level lower than that of a lowest unoccupied molecular orbit (LUMO) of the sensitizing dye. The electrolyte medium comprises an electrolyte and at least one solvent selected from an aprotic solvent and a protic solvent, wherein the electrolyte comprises a salt capable of providing an oxidized sensitizing dye with electrons.