A novel heterogeneous CdSe/CdS/Pt/TiO2 nanotube array photoelectrode (denoted as CdSe/CdS/Pt/TiO2 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/TiO2 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 CLOD) of 2.08 pM and a linear range from 0.1 to 10 mu M. The practical application of the photoelectrochemical immunosensor is also realized in the selective determination of octachlorostyrene in sewage sample. (C) 2014 Elsevier B.V. All rights reserved.