The Electrochemical Sensory Determination Of Pesticides Based On Boron Nitride

With the need to increase food production,herbicides and pesticides such as paraquat and carbaryl have been widely used in agriculture practices.With overused pesticides,the past few decades have witnessed the issues to our environment of pesticide residue.Therefore,monitoring residues in the environment is of great importance.Giving that electrochemical alternatives without any complicated sample pretreatment and easier to operate,the working electrodes modified with mesoporous and nanostructured materials emerged and have been applied in the field of electroanalysis to improve sensitivity and selectivity.Then,an electrochemical sensor based on hexagonal boron nitride for paraquat and carbaryl has been developed.The research contents,results and conclusions are summarized as follows:Boron nitride?BN?synthesized from nitride acid and melamine by solvent-cutting method and was functionalized with molybdenum disulfide?MoS₂?and Au nanoparticles?Au NPs?.With a large surface area and good conductivity,the BN/MoS₂/Au NPs nanocomposites were designed to achieve preferable sensing performances for paraquat.On the optimum conditions,an excellent response signal to paraquat was found from 0.1?M to 100?M with a limit of detection of 0.074?M,and it had acceptable reproducibility?RSD=2.99%,n=5?and good anti-interference ability.The results of the electrochemical analysis agreed with those of experiments and obtained a 96.28%confidence level via high-performance liquid chromatography,exhibiting relatively high stability.Therefore,the fabricated sensor can be a candidate for the determination of paraquat.The glassy carbon electrode was modified with BN and the electrolytic deposited gold nanocrystals?DpAu?for immobilizing AChE.Therefore,electrochemical biosensor based on BN/DpAu/AChE was fabricated for carbaryl detection.Then,the electrochemical analysis methods such as the electrochemical impedance spectrum?EIS?,cyclic voltammetry?CV?and differential pulse voltammetry?DPV?were used to study the electrochemical behavior on AChE/DpAu/BN GCE.With the optimum conditions,the inhibition of carbaryl was proportional to its concentrations ranging from 0.02 to 0.1?g/L.The limit of detection is 0.018?g/L.In a word,the developed electrochemical biosensor showed good sensitivity and stability towards the monitoring of carbaryl pesticides in cabbage with the recovery ranging from 98.26%–102.7%.