Ziram herbicide determination using a polished silver solid amalgam electrode

The development of biopolyol/chitosan modified single-use disposable electrochemical biosensor and its application for the voltammetric monitoring of the biointeraction between ziram and double stranded DNA

The main objective is the present study is to develop a novel and sustainable electrochemical biosensor to monitor genotoxic effect of ziram. For this purpose, pencil graphite electrodes (PGEs) were modified with biopolyol obtained by liquefying olive pomace in polyhydric alcohols with an acid catalyst (BPL) and chitosan (CHIT), and the biointeraction between commercial form of ziram and DNA was performed at the surface of the CHIT/BPL-PGEs. Changes at the cathodic peak current (Ic) measured in 2.00 mM Fe(CN)63-/4- in 0.10 M KCl by cyclic voltammetry (CV) were evaluated for BPL and CHIT modification. Electrochemical and microscopic characterization studies of the CHIT/BPL-PGEs were performed by CV, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX). CHIT was effectively modified on BPL-PGE compared to unmodified PGE, and reproducible, repeatable and stable electrochemical response was obtained using CHIT/BPL-PGEs. Linear sweep voltammetry (LSV) was applied for nucleic acid detection, and the changes at the Ic measured by LSV were evaluated for genotoxicity assessment. Genotoxic effect of ziram could be monitored using CHIT/BPL-PGEs for <30 s with reliable results. The greenness level of the biosensor was found to be 0.79 using Analytical GREEnness Metric Approach and Software (AGREE) which indicated high sustainability.

Development of a novel HPLC-CDCL method utilizing nitrogen-doped carbon dots for sensitive and selective detection of dithiocarbamate pesticides in tea

In this study, S-methyl derivatives of dithiocarbamates (DTCs) were shown to significantly enhance chemiluminescence (CL) between Ce(IV) and efficient and environmentally friendly nitrogen-doped carbon dots (NCDs). Based on the elucidation of the CL mechanisms, an innovative approach involving high-performance liquid chromatography coupled with N-CDs and CL detection (HPLC-CDCL) was proposed. The developed method was successfully applied to the highly sensitive detection of three DTC fungicides (dimethyl dithiocarbamate, ethylene bisdithiocarbamate, and propylene bisdithiocarbamate) in tea. The recovery of the established method ranged 70.51-116.45%, with relative standard deviations (RSD) of <9.40%. The limit of detection (S/N = 3) was as low as 0.19 μg/L (as CS2), which is superior to the previous methods and comparable to UPLC-tandem mass spectrometry (MS/MS). Moreover, the proposed approach does not require solid-phase extraction and offers excellent selectivity. This study proposes a novel method for the detection of DTCs in the food safety and environmental fields.

Pesticides impacts on human health and the environment with their mechanisms of action and possible countermeasures

Pesticides are chemical constituents used to prevent or control pests, including insects, rodents, fungi, weeds, and other unwanted organisms. Despite their advantages in crop production and disease management, the use of pesticides poses significant hazards to the environment and public health. Pesticide elements have now perpetually entered our atmosphere and subsequently contaminated water, food, and soil, leading to health threats ranging from acute to chronic toxicities. Pesticides can cause acute toxicity if a high dose is inhaled, ingested, or comes into contact with the skin or eyes, while prolonged or recurrent exposure to pesticides leads to chronic toxicity. Pesticides produce different types of toxicity, for instance, neurotoxicity, mutagenicity, carcinogenicity, teratogenicity, and endocrine disruption. The toxicity of a pesticide formulation may depend on the specific active ingredient and the presence of synergistic or inert compounds that can enhance or modify its toxicity. Safety concerns are the need of the hour to control contemporary pesticide-induced health hazards. The effectiveness and implementation of the current legislature in providing ample protection for human health and the environment are key concerns. This review explored a comprehensive summary of pesticides regarding their updated impacts on human health and advanced safety concerns with legislation. Implementing regulations, proper training, and education can help mitigate the negative impacts of pesticide use and promote safer and more sustainable agricultural practices.

CoMnOx Nanoflower-Based Smartphone Sensing Platform and Virtual Reality Display for Colorimetric Detection of Ziram and Cu2

Transition metal doping is an ideal strategy to construct multifunctional and efficient nanozymes for biosensing. In this work, a metal-doped CoMnOx nanozyme was designed and synthesized by hydrothermal reaction and high-temperature calcination. Based on its oxidase activity, an "on-off-on" smartphone sensing platform was established to detect ziram and Cu2+. The obtained flower-shaped CoMnOx could exhibit oxidase-, catalase-, and laccase-like activities. The oxidase activity mechanism of CoMnOx was deeply explored. O2 molecules adsorbed on the surface of CoMnOx were activated to produce a large amount of O2·-, and then, O2·- could extract acidic hydrogen from TMB to produce blue oxTMB. Meanwhile, TMB was oxidized directly to the blue product oxTMB via the high redox ability of Co species. According to the excellent oxidase-like activity of CoMnOx, a versatile colorimetric detection platform for ziram and Cu2+ was successfully constructed. The linear detection ranges for ziram and Cu2+ were 5~280 μM and 80~360 μM, and the detection limits were 1.475 μM and 3.906 μM, respectively. In addition, a portable smartphone platform for ziram and Cu2+ sensing was established for instant analysis, showing great application promise in the detection of real samples including environmental soil and water.

Current electroanalytical approaches in the carbamates and dithiocarbamates determination

Pesticides are a suitable tool for controlling plagues and disease vectors. However, their inappropriate use allows for contamination of the environment, soil, water, and foods. Carbamates and dithiocarbamates pesticides present accumulative effects in the human body resulting in hormonal, neurological and reproductive disorders, and some are still suspected or proven to give carcinogenic or mutagenic effects. This review provides a current electroanalytical approach in the carbamates and dithiocarbamates determination, showing the use of voltammetric techniques such as amperometry, cyclic and linear scan, differential pulse, and square wave voltammetry, indicating their advantages, disadvantages, and perspectives in electroanalytical detection of carbamates and dithiocarbamates in natural water and foods. Also are reported the different materials used in the preparation of working electrodes since their choice has an important impact on the success of the analytical applications, resulting in suitable sensitivity, selectivity, stability, and robustness.

Fluorometric determination of ziram using CsPbBr3 quantum dots

A strategy based on CsPbBr₃ quantum dots (QDs) is described for the determination of ziram pesticide. A facile and inert gas-free method was used for the synthesis of CsPbBr₃ QDs. The obtained CsPbBr₃ QDs displayed turn-off fluorescence behavior for ziram. The fluorescence intensity of the CsPbBr₃ QDs (E_x/E_m = 365/516 nm) was inversely proportional to the concentration of ziram (0.10 to 50.0 ppm) with a detection limit of 0.086 ppm. Notably, satisfactory recoveries (100 ± 0.25 to 107 ± 5.72%) were obtained in spiked fruit samples, which demonstrated that this method is capable of detecting ziram in real samples. In addition, the mechanism for the detection of ziram was investigated in detail. According to the results, this mechanism can be tentatively explained by fluorescence quenching originating from the increased surface defects and the structural changes of the CsPbBr₃ QDs. The detection ability of this strategy shows promising applicability in food safety.

Enhanced sustainable electro-generation of a Ni (I) homogeneous electro-catalyst at a silver solid amalgam electrode for the continuous degradation of N2O, NO, DCM, and CB pollutants

This paper reports the sustainable and enhanced generation of a Ni(I) active electro-catalyst using AgSAE as a cathode material for the sustainable degradation of N₂O, NO, dichloromethane (DCM), and chlorobenzene (CB) by electroscrubbing in a series operation. The AgSAE electrode showed 1.66 times higher Ni(I) formation than the Ag metal electrode. The AgSAE achieved 20% ± 2% Ni(I) generation in a highly concentrated alkaline medium, whereas Ag metal only achieved 12% ± 2% Ni(I) generation at the same current density. Electrochemical impedance spectroscopy and voltammetric studies determined that the kinetics of the charge-transfer reaction was also preferential at the AgSAE, with the cathodic peak at -1.26 V vs. Ag/AgCl confirming Ni(I) formation. Initially, the change in the oxygen reduction potential and reduction efficiency of Ni(I) confirmed the removal of N₂O, NO, DCM and CB. In addition, the gas Fourier transform infrared (FTIR) spectrum revealed 99.8% removal efficiency of toxic pollutants. Therefore, the regeneration of Ni(I) confirmed the sustainable removal of toxic pollutants. Furthermore, the FTIR spectra revealed the formation of NH₃ during the reduction of N₂O and NO. On the other hand, DCM and CB were reduced to benzene derivatives in the solution phase. In addition, a plausible reduction mechanism was derived. As a result, the AgSAE cathode exhibited two-fold higher removal efficiency of N₂O, NO, DCM, and CB than the previously reported electrodes.

Advances in the Detection of Dithiocarbamate Fungicides: Opportunities for Biosensors

Dithiocarbamate fungicides (DTFs) are widely used to control various fungal diseases in crops and ornamental plants. Maximum residual limits in the order of ppb-ppm are currently imposed by legislation to prevent toxicity problems associated with excessive use of DTFs. The specific analytical determination of DTFs is complicated by their low solubility in water and organic solvents. This review summarizes the current analytical procedures used for the analysis of DTF, including chromatography, spectroscopy, and sensor-based methods and discusses the challenges related to selectivity, sensitivity, and sample preparation. Biosensors based on enzymatic inhibition demonstrated potential as analytical tools for DTFs and warrant further research, considering novel enzymes from extremophilic sources. Meanwhile, Raman spectroscopy and various sensors appear very promising, provided the selectivity issues are solved.

Rapid detection of ziram residues in apple and pear fruits by SERS based on octanethiol functionalized bimetallic core-shell nanoparticles

Existing approaches for the screening of unsafe materials in food matrices are time-consuming, tiresome and destructive in nature. Therefore, in the current study, a surface-enhanced Raman spectroscopy (SERS) method based on octanethiol-functionalized core-shell nanoparticles (Oct/Au@AgNPs) was established for rapid detection of ziram in apple and pear fruits. The morphology of substrate was evaluated using high-resolution TEM images and superimposed HAADF-STEM-EDS elemental mapping images, which confirmed that Au@AgNPs having gold (Au) core size of 28 nm in diameter and silver (Ag) shell of 5.5 nm in thickness were successfully grafted with octanethiol. The SERS method with the sensitive nanoparticles could detect ziram of up to 0.015 and 0.016 ppm in apple and pear with high coefficients of determination (R²) of 0.9987 and 0.9993, respectively. Furthermore, satisfactory recoveries (80-106%) were also accomplished for the fungicide in real samples. This work demonstrated that the functionalized silver-coated gold nanoparticles were easy to prepare and could be used as sensitive SERS platforms for monitoring of other agrochemicals in foods.