A Highly Sensitive Electrochemical Impedance Spectroscopy Immunosensor for Determination of 1-Pyrenebutyric Acid Based on the Bifunctionality of Nation/Gold Nanoparticles Composite Electrode

摘要

A simple, highly sensitive and label-free electrochemical impedance spectroscopy （EIS） immunosensor was developed using Nation and gold nanoparticles （nano-Au/Nafion） composites for the determination of 1-pyrenebutyric acid （PBA）. Under the optimal conditions, the amount of immobilized antibody was significantly improved on the nano-Au/Nafion electrode due to the synergistic effect and biocompatibility of Nation film and gold nanoparticles composites. The results showed that the sensitivity and stability of nano-Au/Nafion composite electrode for PBA detection were much better than those of nano-Au modified glassy carbon electrode （nano-Au/GCE）. The plot of increased electron transfer resistances （Rets） against the logarithm of PBA concentra- tion is linear over the range from 0.1 to 150 ng·mL-1 with the detection limit of 0.03 ng·mL-1. The selectivity and accuracy of the proposed EIS immunosensor were evaluated with satisfactory results.