Construction of CdS/Ag2S-based broad-spectrum photoelectrochemical immunosensor for simultaneous assessment of ochratoxins by multivariable linear regression

A broad-spectrum photoelectrochemical (PEC) immunoassay was established to detect ochratoxins by using the CdS nanorod arrays (CdS NRs)/Ag2S on FTO as the photoelectrode and the CuO@secondary antibody (Ab2) label as the signal amplification. Due to the advantages of broad-spectrum antibody, such immunosensor exhibits high sensitivity to detect a low concentration of 0.67 ng/L ochratoxin A (OTA), 0.85 ng/L ochratoxin B (OTB) and 0.46 ng/L ochratoxin C (OTC), respectively. Especially, the orthogonal test was used to simulate an actual mixture containing OTA, OTB and OTC, then a multivariable linear regression model was applied to analyze the relationship of the total response with each substance. Finally, the detection of unknown mixture containing different ochratoxins was achieved by the standard addition. Such immunosensor also provided a credible selectivity and stability, suggesting its potential to detect ochratoxins or other similar compounds in food and environment.