A label-free electrochemical bisphenol A immunosensor based on chlorogenic acid as a redox probe
A simple and sensitive electrochemical immunosensor for bisphenol A was prepared with an acetylene black–chitosan–gold composite (AB–CS–Au) and gold nanoparticles (AuNPs) as electrode modifiers and chlorogenic acid (CGA) as the redox probe. AB–CS–Au acted as a signal amplifier and anti-BPA was immobilized at the modified electrode using AuNPs to capture bisphenol A in a sample solution. After some factors such as pH of the supporting electrolyte and immunoreaction time were optimized, a quantitative detection of bisphenol A was established in the range of 7.5 × 10−9−1.0 × 10−6 M with a limit of detection (LOD) and quantitation (LOQ) of 6.4 × 10−9 M (3 σ/k) and 2.1 × 10−8 M (10 σ/k), respectively. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were applied to characterize the construction procedures of the immunosensor. The ascribed immunosensor yielded good results in terms of specificity, stability and reproducibility and was successfully applied to sample analysis with accuracy.