Determination of carbendazim in soil samples by anodic stripping voltammetry using a carbon fiber ultramicroelectrode

2D/1D VSe2/MWCNT hybrid-based electrochemical sensor for carbendazim quantification of environmental, food, and biological samples

For the first time the sensitive determination of carbendatim (CRB) is reported utilizing a well-designed sensing architecture based on vanadium diselenide-multiwalled carbon nanotube (VSMC). FTIR, XRD, FESEM, EDS, and EIS were employed to evaluate the sensor's structural integrity, and the results demonstrated the successful integration of nanomaterials, resulting in a robust and sensitive electrochemical sensor. Cyclic voltammetry (CV) and chronoamperometric (CA) investigations showed that the sensor best performed at pH 8.0 (BRB) with an excellent detection limit of 9.80 nM with a wide linear range of 0.1 to 10.0 µM. A more thermodynamically viable oxidation of CRB was observed at the VSMC/GCE, with a shift of 200 mV in peak potential towards the less positive side compared with the unmodified GCE. In addition, the sensor demonstrated facile heterogeneous electron transfer, favorable anti-fouling traits in the presence of a wide range of interferents, good stability, and reproducible analytical performance. Finally, the developed sensor was validated for real-time quantification of CRB from spiked water, food, and bio-samples, which depicted acceptable recoveries (98.6 to 101.5%) with RSD values between 0.35 and 2.23%. Further, to derive the possible sensing mechanism, the valence orbitals projected density of states (PDOS) for C, H, and N atoms of an isolated CRB molecule, VSe2 + CNT and VSe2 + CNT + CRB were calculated using density functional theory (DFT) calculations. The dominant charge transfer from the valence 2p-orbitals of the C and N atoms of CRB to CNT is responsible for the electrochemical sensing of CRB molecules.

Electroanalytical overview: the sensing of carbendazim

Carbendazim is a broad-spectrum systemic fungicide that is used to control various fungal diseases in agriculture, horticulture, and forestry. Carbendazim is also used in post-harvest applications to prevent fungal growth on fruits and vegetables during storage and transportation. Carbendazim is regulated in many countries and banned in others, thus, there is a need for the sensing of carbendazim to ensure that high levels are avoided which can result in potential health risks. One approach is the use of electroanalytical sensors which present a rapid, but highly selective and sensitive output, whilst being economical and providing portable sensing platforms to support on-site analysis. In this minireview, we report on the electroanalytical sensing of carbendazim overviewing recent advances, helping to elucidate the electrochemical mechanism and provide conclusions and future perspectives of this field.

Development of 2D graphene oxide sheets-based voltammetric sensor for electrochemical sensing of fungicide, carbendazim

Incorporating new pollutants and environmental pollution has become a formidable issue as new pollutants are introduced into it and have become a significant concern in recent years. Detection of such pollutants needs a susceptible, selective, and cost-effective sensor that can sense their presence and quantify them at a trace level. In the present study, we have designed a 2D graphene oxide (GO)-based glassy carbon electrode (GCE) electrochemical sensor (GO/GCE) and utilized it as a sensing material for the detection and determination of CRZ. The voltammetric behavior of CRZ was studied using cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques. The SWV was applied to quantify and analyze CRZ in actual samples. A better response of CRZ was noticed at GO/GCE when phosphate buffer solution of pH 4.2 was used as a supporting electrolyte for to experiment. The SWV technique achieved trace-level detection of CRZ. A linearity plot was obtained for the concentration range of 1.0 × 10^-7 M to 2.5 × 10^-4 M with a limit of detection of 1.38 × 10^-8 M. The selectivity of the modified sensor was verified by the interference study of metal ions and other pesticides with CRZ. The agricultural and environmental significance of the developed method was successfully tested by estimating CRZ in water and soil samples.

Biodegradation of carbendazim by a potent novel Chryseobacterium sp. JAS14 and plant growth promoting Aeromonas caviae JAS15 with subsequent toxicity analysis

In the present study, carbendazim (MBC) degrading bacterial strains were isolated and identified as Chryseobacterium sp. JAS14 and Aeromonas caviae JAS15. Both the strains completely degraded 200 mg l^-1 of MBC in the aqueous medium and soil within 4-9 days of incubation. In an aqueous medium, the degradation process was characterized by a rate constant of 53.16 day^-1 and 42.60 day^-1, following zero order model and DT₅₀ was 1.8 days and 2.34 days for Chryseobacterium sp. JAS14 and A. caviae JAS15, respectively. A Chryseobacterium sp. JAS14 and A. caviae JAS15 inoculated into the soil without the addition of nutrients showed the degradation rate constant of 27.30 day^-1 and 23.87 day^-1, and DT₅₀ was 3.66 days and 4.18 days, respectively. The metabolites during MBC biodegradation by Chryseobacterium sp. JAS14 and A. caviae JAS15 were identified as 2-aminobenzimidazole, 2-hydroxybenzimidazole, 1, 2 diaminobenzene and catechol. To our knowledge, this is the first study of the detailed biodegradation pathway of MBC by Chryseobacterium sp. JAS14 was proposed. Phytotoxicity and cytogenotoxicity assays showed that the toxicity of the MBC reduced after biodegradation by Chryseobacterium sp. JAS14 and A. caviae JAS15. In addition, A. caviae JAS15 possess important plant growth promoting traits under normal and MBC stress condition. These results suggest the Chryseobacterium sp. JAS14 and A. caviae JAS15 could be used as a bioresource for the reclamation of MBC contaminated soil.

Cyto-genotoxic consequences of carbendazim treatment monitored by cytogenetical analysis using Allium root tip bioassay

Environmental pollution is one of the major problems of these days. One of the reasons of environmental pollution is the indiscriminate use of agrochemicals in agriculture. Fungicides are being extensively used in agriculture for enhancing crop yield and growth by controlling fungal growth. Fungicide carbendazim is widely applied to soil and seeds of vegetable/cereal crops in India and is effective against a very broad spectrum of fungi. The present study was designed to monitor the cyto-genotoxic effects of carbendazim directly in treated soils by cytogenetical analysis using Allium cepa root tip bioassay. In a pot experiment, fungicide carbendazim was added to soil at the rates of 2.5, 5, 7.5, and 10 mg kg^-1 soil and uniform size onion bulb was planted in each pot, and three replicates were maintained for each dose at 1, 7, 15, 30, and 45 days after application and roots from onion bulbs were fixed for cytogenetical analysis. Findings indicate that carbendazim treatment leads to a significant dose and duration-dependent decrease in percent mitotic index with related increase in mitotic inhibition. Statistical analysis showed a significant effect of carbendazim doses and duration of treatment on the percentage relative abnormality rate of A. cepa. Phase indices of our study showed high numbers of cells in prophase as compared to other phases at some doses of treatment. The different types of chromosomal abnormalities observed in our study serve as indicators of genotoxicity of carbendazim and we report for the first time the effect of its application directly in soil using a plant test system.

Ultrasensitive determination of carbendazim in water and orange juice using a carbon paste electrode

A carbon paste electrode was used for the electrochemical quantification of carbendazim in water and orange juice samples. Carbendazim oxidation on the electrode surface was found to be controlled by adsorption. The novel electrochemical procedure for carbendazim quantification employed differential pulse voltammetry using a carbon paste electrode under optimal conditions. Carbendazim oxidation currents were linear at concentrations of 2.84 to 45.44 µg L(-1), with a limit of detection of 0.96 µg L(-1). The proposed method was applied to carbendazim quantification in ultrapurified water, river water, and orange juice. Recovery rates in water and orange juice samples were in the 97%-101% range, indicating that the method can be employed to determine carbendazim in these matrices, with advantages including shorter analysis time and lower cost than routine methods such as chromatography or spectroscopy. The electrode showed good reproducibility, remarkable stability, and especially good surface renewability by simple mechanical polishing. The recovery rates observed were highly concordant with those obtained for high-performance liquid chromatography, having a relative standard deviation of less than 1.3%.