Green synthesis approach and applications of engineered nanomaterials in food safety

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Nowadays, food safety has received more awareness because of increasing foodborne illness outbreaks around the world that involved biological and chemical substances. Therefore, there are growing interests in using the emerging novel nanomaterials to solve food safety issues. However, the wide use of nanomaterials in the manufacturing of different products, especially in the food industry, raises more concerns about their toxicity and harmful effects on human health since flammable and hazardous substances are used in the synthesis process of these materials. This dissertation aimed to use nanomaterials (silver or gold nanoparticles, nanorods) as novel surface-enhanced Raman spectroscopy (SERS) substrates to detect chemical contaminants in various matrices of food samples, and use green chemistry methods to establish an environmentally-friendly procedure for the synthesis of green nanoparticles. Specific objectives of this study were to: (i) develop a facile and reproducible procedure to prepare standing gold nanorod arrays. The gold nanorod arrays can be coupled with the SERS technique to detect pesticides in fruit juice and milk samples; (ii) use plant extract to synthesize silver nanoparticles (AgNPs) and investigate their antibacterial activity against foodborne bacteria in broth and chicken meat; and (iii) evaluate the toxicity of green synthesized AgNPs on human colon cancerous epithelial (Caco-2) cells and human intestinal bacteria.