| Herbicides are significantly vital in preventing the worst weed and ensuring food supply.However,the residue problem caused by excessive use has seriously toxic effects on environment protection,agricultural production,and human health.Hence,it is necessary to develop an easy,rapid,and sensitive approach for the herbicide detection.At present,many analysis methods have been widely employed for the determination of herbicide,such as liquid chromatography,gas chromatography,and capillary electrophoresis,etc.However,these methods generally possess the disadvantage of complicated working procedures,highly trained operators,and high equipment cost,which makes it difficult to meet the demand for high-efficient and large-scale detection to herbicide.Compared with the above methods,electrochemical sensor possesses the advantages of short analysis time,low cost,simple operation,and high sensitivity,thus showing strong application value in the field of herbicide residue detection.In recent years,the electrochemical sensors based on nanomaterials with catalysis,adsorption and signal amplification have become an emerging research hotspot in the field of herbicide residue detection.In this work,a variety of nanocomposites were successfully prepared by using ultrasonic-assisted strategy,and then three novel nanocomposite based electrochemical sensor were successfully constructed by using functional nanocomposites coupled with efficient and convenient electrochemical sensing technology,which were applied to the rapid and sensitive detection of herbicide residues.The herbicide residue analysis methods proposed in this work have achieved good detection limit,sensitivity,selectivity,reproducibility,and stability.The specific research contents are as follows:（1）The graphitized multi-walled carbon nanotubes@Super P Li（GCNTs@Super-P）nanocomposite was successfully developed via a simple ultrasonication-assisted strategy,and then the GCNTs@Super-P/GCE sensor based on the synthesized GCNTs@Super-P nanocomposite decorating glassy carbon electrode（GCE）was successfully applied in the sensitive detection of isoproturon（ISO）.Benefiting from the synergistic effect of GCNTs and Super-P,the optimized GCNTs@Super-P/GCE sensor showed good detection performance with the detection limit of 0.0946μM.Additionally,the proposed sensor exhibited satisfactory recoveries towards the detection of ISO in river water and tap water,confirming excellent practical feasibility of the GCNTs@Super-P/GCE sensor.（2）A simple,low-cost,and scalable ultrasonication-assisted strategy was proposed to fabricate the composite of Super-P carbon black nanoparticles dispersed palygorskite（Pal）nanofiber,which was employed to construct an electrochemical sensor for DQ determination.The Pal/Super-P/GCE sensor exhibited ultrasensitive determination performance with a low detection limit（0.1514 n M）and high sensitivity(44.141μAμM-1)in the linear DQ concentration range of 0.00050-1.0μM.The recoveries of the constructed sensor ranged from95.6%to 100.3%when applied to detect DQ in river water,potato,and cucumber.The above enhanced DQ detection performance was primarily due to the synergistic effect of Pal and Super-P.（3）Porous COFs spheres and GCNTs together construct the COFs@GCNTs nanocomposite with core-shell structure via a room-temperature synthesis strategy,which was employed to decorate GCE for highly sensitive detection of diuron（DU）.The COFs@GCNTs/GCE sensor presents a wide linear concentration range of 0.3–18μM with low detection limit of 0.08μM（S/N=3）and a high sensitivity of 11.33μAμM-1cm-2.Furthermore,the optimized sensor was successfully applied in the detection of DU in river water,tomato,and cucumber samples with satisfactory recoveries. |
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