Zinc sulfide nanoparticles (ZnS NPs) are extensively studied for their application in various fields including using their fluorescent property for bio-imaging. In this project, ZnS NPs were modified to be antimicrobial active in addition to their fluorescent properties through surface oxidation with hydrogen peroxide. A series of peroxide concentrations were studied and labelled HPT-1 to HPT-4 (hydrogen peroxide treated). The NPs were characterized with UV-Vis and Fluorescence spectroscopy; the least peroxide concentration treated sample (HPT-1) showed fluorescent intensity enhancement up to 1.4 times, however higher peroxide treatment (HPT-3) quenched the fluorescence . Minimal inhibitory concentration (MIC) study showed antimicrobial efficacy as low as 125 ppm of metallic Zn when ZnS NPs are treated with peroxide in contrast to no killing at 2000ppm or less for untreated ZnS NPs. To evaluate their safe application in a biological system, Alamar blue assay on human dermal fibroblast cell (HDF) was performed which revealed that cytotoxicity increased with increasing peroxide treatment. Highest treated peroxide concentration (HPT-4) showed the most killing activity for both bacteria and human cell lines but at the expense of loss of fluorescent property. However, HPT-2 is a sample of interest since it showed a 1.2 times increase in fluorescent intensity and antimicrobial efficacy at 250 ppm with minimal mammalian toxicity. Therefore, using its dual properties it can serve as a model system to understand the translocation and fate of similar antimicrobial NPs.

Development of antimicrobial and fluorescent ZnS:Mn nanoparticles

2019 Spring National Meeting

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