Photoelectrochemical label-free immunoassay of octachlorostyrene based on heterogeneous CdSe/CdS/Pt/TiO2 nanotube array

Abstract A novel heterogeneous CdSe/CdS/Pt/TiO 2 nanotube array photoelectrode (denoted as CdSe/CdS/Pt/TiO 2 NTA) was developed by dipping and deposition technique as well as successive ionic layer adsorption and reaction (SILAR). An octachlorostyrene (OCS) photoelectrochemical immunosensor was constructed by cross-linking anti-OCS antibody onto the CdSe/CdS/Pt/TiO 2 NTA using anti-OCS antibody prepared in this laboratory. The as-prepared photoelectrochemical immunosensor is highly stable, sensitive and selective to octachlorostyrene with a limit of detection (LOD) of 2.08 pM and a linear range from 0.1 to 10 μM. The practical application of the photoelectrochemical immunosensor is also realized in the selective determination of octachlorostyrene in sewage sample.