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

Abstract

A simple, highly sensitive and label‐free electrochemical impedance spectroscopy (EIS) immunosensor was developed using Nafion 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 Nafion 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 concentration 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.

An Immunosensor for Ultrasensitive Detection of 1‐Pyrenebutyric Acid with Enhanced Electrochemical Performance Based on a Graphene‐Ionic Liquid Doped Chitosan Film Modified Glassy Carbon Electrode

“…The detection limit was estimated to be 0.01 ng/mL based on a signal to noise ratio of 3. The detection limit of this immunosensor was better than those of previously reported PBA immunosensors based on GS‐CS modified electrode (0.1 ng mL −1 ), and Nafion/gold nanoparticles composite modified Electrode (0.1 ng mL −1 ) 26.…”

Heparin‐gold Nanoparticles and Liquid Crystal Applied in Label‐free Electrochemical Immunosensor for Prostate‐specific Antigen

“…The GE/Br−Py/AuNP‐Hep‐Nafion (c) showed a decrease in the peak current in relation to the sensor (b), attributed to the presence of the heparin and Nafion (nonconducting polymers). The heparin was used as a stabilizing agent for nanoparticles, and the Nafion confers physical stability to the film avoiding its leaching . Moreover, the AuNP‐Hep‐Nafion film offers good biocompatibility and a large specific surface area for antibody immobilization by physical adsorption .…”

“…The heparin was used as a stabilizing agent for nanoparticles, and the Nafion confers physical stability to the film avoiding its leaching . Moreover, the AuNP‐Hep‐Nafion film offers good biocompatibility and a large specific surface area for antibody immobilization by physical adsorption . The effective surface area of AuNP‐modified electrode compared to the bare GE was studied thoroughly at a series of scan rates ranging from 25 to 150 mV s −1 (Figure S2 and S3).…”

“…The GE/Br−Py/AuNP‐Hep‐Nafion/ab‐PSA/Gly (d) also showed a decrease in the peak current, due to the ab‐PSA immobilization step, followed by blocking step of non‐specific sites with glycine (Gly). When ab‐PSA molecules were immobilized by physical adsorption on the GE/Br−Py/AuNP‐Hep‐Nafion surface, the response currents decreased, due to the formation of a protein film that obstructs the interfacial electron transfer . After the PSA antigen incubation (curve “e”), the proposed immunosensor showed a decrease in the peak current due to the specific binding of the antigen with the immobilized antibody.…”

A sensitive electrochemical impedance immunosensor for determination of malachite green and leucomalachite green in the aqueous environment

“…Among these, the electrochemical impedance-based immunosensor (EIS) [13,14] is one of the most efficient and sensitive methods. An impedimetric immunosensor is based on the detection of the binding between an immobilized antibody and an antigen [15] and is more amenable for miniaturization and economization [16]. Some electrochemical impedimetric immunosensors have been built to detect contaminants, but the detection of MG and LMG has not been reported.…”