Highly efficient antimicrobial agents with low toxicity and resistance have been enthusiastically pursued to address public concerns on microbial contamination in food. Silver nanoclusters (AgNCs) are known for their ultrasmall sizes and unique optical as well as chemical properties. Despite extensive studies of AgNCs for biomedical applications, their application as antimicrobials remains to be explored. Here, for the first time, by incorporating AgNCs (~ 2 nm in diameter) to zein films that are widely used as food packaging materials, we developed a novel antimicrobial coating material with potent antimicrobial activity, low toxicity to human cells, and low harm to the environment. In addition, we systematically evaluated the antimicrobial activities and cytotoxicity of AgNC-embedded zein films and compared them with zein films embedded with AgNO3 or Ag nanoparticles with diameters of 10 nm and 60 nm (AgNP10 and AgNP60, respectively). At the same concentrations of silver equivalents, AgNCs and AgNO3 solution exhibited comparable antimicrobial activities that were dramatically higher than those of AgNP10 and AgNP60. Moreover, AgNCs presented less cytotoxicity to human cells than AgNO3, with half maximal inhibitory concentration (IC50) of 34.68 mg/mL for AgNCs compared to 9.14 mg/mL for AgNO3. Altogether, the high antimicrobial efficacy, ultrasmall sizes and low cytotoxicity of AgNCs demonstrated their great potential in antimicrobial applications.

Silver nanoclusters embedded zein films as antimicrobial coating materials for food packaging

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.