Gold nanoparticle-based colorimetric and electrochemical sensors for the detection of illegal food additives

Lately, scandals associated with the illegal addition of poisonous chemicals to food for commercial interests have been gradually disclosed to the public. Problems related to food safety do not only harm public health but also affect the stability of economic and social development. Food safety has become a common issue in society, and strengthening the related regulations have become increasingly important. Although conventional techniques are accurate and sensitive in the detection of the vast majority of illegal food additives, they rely on time-consuming, labor-intensive procedures that depend on expensive instruments. Thus, efficient and rapid identification of poisonous, illegal additives in food is a crucial task in analytical chemistry. Recently, in this context, gold nanoparticles (GNPs) have attracted considerable attention because of their optical, electronic, catalytic, and chemical properties. Their excellent properties have facilitated the widespread use of GNPs in different sensors. This review covers the two most common GNP-based sensors with colorimetric and electrochemical responses, which have proven to be effective in the detection of illegal additives. The GNP-based sensors comply with the requirement of modern analysis, such as high selectivity, sensitivity, simplicity, rapidity, and portability. Thus, they have great potential as powerful sensing tools for food safety screening. This review elucidates the utility and advances of GNP-based colorimetric and electrochemical sensors for the detection of illegal additives in the food industry and in the supervision of food quality and safety. Additionally, an outlook of the trends and future development of research on these sensors is provided.