An Amperometric Immunosensor Based on Multi-Walled Carbon Nanotubes-Thionine-Chitosan Nanocomposite Film for Chlorpyrifos Detection

Abstract

In this work, a novel amperometric immunosensor based on multi-walled carbon nanotubes-thionine-chitosan (MWCNTs-THI-CHIT) nanocomposite film as electrode modified material was developed for the detection of chlorpyrifos residues. The nanocomposite film was dropped onto a glassy carbon electrode (GCE), and then the anti-chlorpyrifos monoclonal antibody was covalently immobilized onto the surface of MWCNTs-THI-CHIT/GCE using the crosslinking agent glutaraldehyde (GA). The modification procedure was characterized by using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimized conditions, a linear relationship between the relative change in peak current of different pulse voltammetry (DPV) and the logarithm of chlorpyrifos solution concentration was obtained in the range from 0.1 to 1.0 × 105 ng/mL with a detection limit of 0.046 ng/mL. The proposed chlorpyrifos immunosensor exhibited high reproducibility, stability, and good selectivity and regeneration, making it a potential alternative tool for ultrasensitive detection of chlorpyrifos residues in vegetables and fruits.

Electrochemical devices for the detection of priority pollutants listed in the EU water framework directive

“…Provided that the production of antibodies against small molecules such as pesticides is a difficult and costly process, most of the work developed in this area has been focused on the detection of atrazine, for which specific antibodies have been developed and thoroughly assessed (Table 3) [64][65][66][67][68][69][70][71]. Examples of electrochemical immunosensors for chlorpyrifos [72], diuron [73,74], isoproturon [75] and endosulfan [76] have also been found in the literature ( Among the immunosensor formats applied for pesticide analysis, label-free reagentless approaches should be mentioned [70,71,76]. Label-free and reagentless immunosensors are systems capable to measure a target analyte after the corresponding affinity interaction without the need of additional reagents.…”

“…[Fe(CN) 6 ] 3−/4 ) to get the electrochemical signal [65,66,68,72]. Electrochemical detection for these label-free immunosensors was based on the change of electron transfer kinetics of the redox-probe at the electrode-solution interface, due to the corresponding affinity reaction [65,66,68,72].…”

Extended Bio-Analytical Approach for the Determination of Potential Toxicants

“…However, between t = 0 and t = t 1 (maximal incubation time) minutes, current intensity values measured in the presence of an inhibitor fluctuate a lot. 27 Relative standard deviation calculated for repeatability and mean current ± 3 × standard deviation calculated for stability support the fluctuations in the amperometric current. Furthermore, the percentage inhibition calculated at different incubation time intervals for a particular inhibitor concentration tells about the overview of toxicity of an inhibitor to enzyme.…”

A Label-Free Microelectrode Array Based on One-Step Synthesis of Chitosan–Multi-Walled Carbon Nanotube–Thionine for Ultrasensitive Detection of Carcinoembryonic Antigen

“…Therefore, the selection of catalytic material is as important as the redox species. Multi-walled carbon nanotubes (MWCNTs) have many advantages as a catalytic material over other materials, including high chemical stability, high tensile strength, being nano-sized, high surface area, excellent stiffness, and high electrical conductivity [24,25]. Additionally, the high effective surface area and reactive functional groups are benefits that allow loading high-density redox species and increasing the electrochemical currents [26,27,28].…”