Ratiometric Strategy for Electrochemical Sensing of Carbaryl Residue in Water and Vegetable Samples

Abstract

Accurate analysis of pesticide residue in real samples is essential for food safety and environmental protection. However, a traditional electrochemical sensor based on single-signal output is easily affected by background noise, environmental conditions, electrode diversity, and a complex matrix of samples, leading to extremely low accuracy. Hence, in this paper, a ratiometric strategy based on dual-signal output was adopted to build inner correction for sensing of widely-used carbaryl (CBL) for the first time. By comparison, Nile blue A (NB) was selected as reference probe, due to its well-defined peak, few effects on the target peak of CBL, and excellent stability. The effects of a derivatization method, technique mode, and pH were also investigated. Then the performance of the proposed ratiometric sensor was assessed in terms of three aspects including the elimination of system noise, electrode deviation and matrix effect. Compared with traditional single-signal sensor, the ratiometric sensor showed a much better linear correlation coefficient (r > 0.99), reproducibility (RSD < 10%), and limit of detection (LOD = 1.0 μM). The results indicated the introduction of proper reference probe could ensure the interdependence of target and reference signal on the same sensing environment, thus inner correction was fulfilled, which provided a promising tool for accurate analysis.

Unveiling the effect of crystallinity and particle size of biogenic Ag/ZnO nanocomposites on the electrochemical sensing performance of carbaryl detection in agricultural products

“…The oxidation of CBR in the presence of Ag/ZnO NCs was proposed by two processes as follows: 11,49,50 (1) In alkaline media with adding of NaOH, CBR molecules were hydrolyzed to 1-naphthol.…”

Strategy of In Situ Electrochemical Regulation for Highly Enhanced Nonenzymatic Sensing of Carbaryl

“…Although the proposed e-GCE CP−CV was not sensitive toward the group of −OH, many other modified electrodes could largely enhance this oxidation peak current but fail to distinguish each of the carbamate insecticides. 34,35 However, compared with other carbamate insecticides with one benzene ring, the hydrolyzed product of 1-naphthol from CBL with two benzene rings has active chemical properties that it can be transformed into various derivatives through electrochemical regulation, 33,36,37 and is more likely to be adsorbed on the surface of the carbon-based electrode via the π−π bond. As mentioned above, 1-naphthol could be transformed to 1,4-naphthoquinone on the surface of proposed e-GCE CP−CV during the facile process of regulation III, giving rise to a reduction peak at −0.25 V. In that case, the constructed sensor can avoid interference of other carbamate insecticides by detecting the electrochemical signal of the specific derivative.…”

Electrochemical Synthesis of Reduced Graphene Oxide/Gold Nanoparticles in a Single Step for Carbaryl Detection in Water

“…Moreover, enzymes employed as sensors require specific handling in terms of storage, temperature, enzyme activity, pH and applied potential, which makes these devices more complicated to deal with and less consistent in terms of reliability [ 11 ]. Recently, non-enzymatic methods have been reported which require the hydrolysis of carbaryl to carbaryl–phenol ( Figure 1 ) to enhance the electrochemical reaction [ 12 , 13 ]. However, it was reported that carbamate residues can be detected directly, electrochemically, without the requirement for the target analytes to be first hydrolyzed [ 14 , 15 , 16 ].…”