Highly sensitive photoelectrochemical neuron specific enolase analysis based on cerium and silver Co-Doped Sb2WO6.

A signal-enhanced photoelectrochemical immunoassay technique for detecting neuron specific enolase (NSE) was proposed. As a photoactive matrix, (Ce,Ag):Sb2WO6 was firstly investigated via doping Ce and Ag into Sb2WO6. It could be found that the presence of Ce and Ag not only had enormous variation on the morphology of Sb2WO6, but also showed excellent PEC behavior. In order to further improve the visible light utilization rate of (Ce,Ag):Sb2WO6, In2S3 was modified onto the surface of (Ce,Ag):Sb2WO6 to enhance visible light absorption. In addition, the CdS/PDA was served as a secondary antibody marker to further amplify signal. Especially, PDA as an electron donor could effectively remove photogenerated holes. Meanwhile, the good matching cascade band-edge levels between CdS and Sb2WO6 could promote photoelectron migration, improve the PEC response, and achieve sensitive detection of NSE. Under the selected excellent conditions, the photocurrent can linearly increase with the increase of NSE concentration in the operating range from 0.1 pg/mL to 50 ng/mL, and the limit of detection is 1.57 fg/mL. The constructed immunosensor also exhibits satisfactory stability, selectivity, and reproducibility, and it creates conditions for the detection of other biomolecules.