A New Method For Colorimetric Detection Of Food Hazards Based On The Catalytic Activity Of Layered Tungsten Disulfide

There are many types of food hazards,such as heavy metals,antibiotics,pesticides,etc.Some environmental pollution or human factors can cause their excessive residues in food,which in turn leads to a series of food safety problems.The common methods of food analysis are mainly instrumental methods,which has the advantages of high sensitivity and reliable results.However,they are not conducive to the real-time detection of massive samples due to the need of expensive equipments,professional operators,and tedious pretreatment.Recently,researchers have established a series of fluorescence,electrochemical,and colorimetric for food detection.The colorimetric method is the simplest strategy that can easily meet the demands of point-of-care and ease-of-use for antibiotics detection.However,the existing colorimetric methods facing many challenges,such as unstable sensing materials,narrow temperature ranges,large batch differences,and ease of false positives.Hence,it is urgent to construct more stable and robust colorimetric methods for the detection of food hazards.Two-dimentional layered tungsten disulfide（WS₂）nanosheets with rich active edge exhibit intrinsic peroxidase-mimic activity,which make them an ideal material for sensor design.However,there is still a lack of research on the application of WS₂ nanosheets in the field of food safety.Herein,two-dimensional WS₂ nanosheets are used as the output material of colorimetric sensing signals,combined with the regulation effect of lead and aptamer on the peroxidase-mimic activity of nanosheets,to construct two new colorimetric sensors for the rapid detection of lead and kanamycin in food samples.The constructed colorimetric sensors have the advantages of simplicity and stability,providing fast and efficient alternatives for large-scale and on-site detection of actual food samples.