Gold nanoparticles: From synthesis, properties to their potential application as colorimetric sensors in food safety screening

Background: Food safety management and guarantee are the basic requirement during food processing, circulation, storage, and marketing. Elevating the ability to evaluate food quality and safety in a rapid, sensitive and reliable manner is of great importance in food industry. Recently, gold nanoparticles due to unique optical property, ease of ftuictionalization and preparation, and high selectivity and sensitivity have received considerable attention in the field of food safety. Scope and approach: Gold nanoparticles exhibit distinguishable optical characteristic in different aggregated states and thus have been developed into simple colorimetric sensors for the quick detection of chemical contaminants in food samples. Herein, we reviewed the current methods for synthesis and functionalization of gold nanoparticles, strategies for fabrication of gold nanoparticle based colorimetric sensors and their applications in rapid analysis of food contaminant. Moreover, the inherent optical property of gold nanoparticles and their detecting principle have been highlighted. Finally, the main challenges and future efforts in developing such colorimetric sensors for food contaminants detection were discussed. Key findings and conclusions: Gold nanoparticles as smart colorimetric sensors conform to the requirement of modern analysis, such as high selectivity, sensitivity, simplicity, celerity, and portability. Thus, they have great potential to be applied as power sensing tools for food safety screening.