A novel and label-free immunosensor for bisphenol A using rutin as the redox probe

• A simple and label-free immunosensor of bisphenol A was fabricated.
• MWCNTs and AuNPs were introduced to enhance current response.
• Rutin was used as the redox probe to construct bisphenol A immunosensor.
• The proposed method was applied in bisphenol A detection in food fresh-keeping film.

In this work, a new and label-free electrochemical immunosensor for sensitive detection of bisphenol A was reported. MWCNTs and gold nanoparticles (AuNPs) were modified on glassy carbon electrode surface to enhance current response. The Anti-BPA was immobilized on the modified electrode through AuNPs. Rutin was used for the first time as the redox probe to construct electrochemical immunosensor of bisphenol A. The peak current change due to the specific immuno-interaction between anti-BPA and BPA on the modified electrode surface was utilized to detect bisphenol A. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) were employed to trace the assembly process of the electrochemical immunosensor. Experimental factors affecting the sensitivity of the immunosensor were examined in terms of incubation time and pH of phosphate buffer solution (PBS). Under optimized conditions, the linear range of calibration curve based on the relationship between current response and BPA concentration was from 1.0×10−8–1.0×10−6 M with detection limit of 8.7×10−9 M (S/N=3). The proposed immunosensor showed good reproducibility, selectivity, stability and was successfully applied to the determination of BPA in real sample.

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