Emerging nanolabels-based immunoassays: principle and applications in food safety

Abstract Food safety issues pose a serious threat to human health, and appropriate detection technologies can effectively ensure food safety. Immunoassay is the gold standard for highly sensitive detection of biochemical targets, providing a good platform for food contaminants detection. In immunoassay, the antibody or antigen conjugated labels are the most important units because they play roles to convert the information of target analytes to easily detected signal. Recently, various efforts have been paid into the label design to enhance the detection sensitivity and stability. Nanomaterials own advantages such as facile preparation, excellent stability, low cost and multi-category signal output, showing great potential as novel label. Herein, we summarize the advances of nanolabels in immunoassays, covering nanomaterials as nanozymes, direct signal indicators, enzyme carriers, etc. Moreover, applications of nanolabels-based immunoassays in the detection of food contaminants (pathogenic microorganisms, allergic proteins, biotoxins, and others) are comprehensively concluded. Finally, challenges and perspectives on the future trends are also proposed.