Charge recombination suppression-based photoelectrochemical strategy for detection of dopamine

Abstract

A new photoelectrochemical strategy based on charge recombination suppression is designed for the selective detection of dopamine. The photoelectrochemical platform was fabricated by simply coating the surface-unpassivated CdTe quantum dots (QDs) on the fluorine-doped tin oxide (FTO). When QDs were excited by light with the wavelength of 405nm, the charge separations were generated, and then some electrons transformed to O2 to produce O2−, leading to the photocurrent. Electron donors, whose energy level lies between the conduction band and valance band of QDs, could inhibit the charge recombination so that the photoelectric conversion efficiency is enhanced. Based on the recombination suppression, a new photoelectrochemical strategy was developed for the selective detection of dopamine. The photoelectrochemical system shows a good performance with the 5-order wide linear range of 4.0×10−7M to 1.0×10−2M, and a detection limit of 1.7×10−7M. This recombination suppression-based photoelectrochemical strategy could be extensively used in other donors-semiconductor material systems.