OICC Press Journal of Nanostructure in Chemistry 2193-8865 12 3 (June 2022) 2021 07 13 Enhanced functionality of green synthesized sulfur nanoparticles using kiwifruit (Actinidia deliciosa) peel polyphenols as capping agents 10.1007/s40097-021-00422-9 EN Ruchir Priyadarshi Department of Food and Nutrition, BioNanocomposite Research Institute, Kyung Hee University, Seoul, 02447, KR Swarup Roy Department of Food and Nutrition, BioNanocomposite Research Institute, Kyung Hee University, Seoul, 02447, KR Jong-Whan Rhim Department of Food and Nutrition, BioNanocomposite Research Institute, Kyung Hee University, Seoul, 02447, KR Journal Article 2021 07 13 Abstract Sulfur nanoparticles (SNPs) have recently caught the scientific community's attention due to their improved physicochemical attributes compared to the bulk counterparts. However, the SNPs' high hydrophobicity and instability in aqueous solutions have limited their actual application potential. Here, kiwifruit peel polyphenols were used as natural capping agents obtained from agro-waste to cap SNPs. The capped particles were ~ 90 nm in size, smaller than ~ 130 nm for uncapped particles. After capping, the zeta potential value was − 45 mV, which is way better than − 28 mV for uncapped particles indicating better dispersion and stability in the aqueous suspension. The XPS spectra of SNPs confirmed successful capping by organic kiwi peel polyphenols showing intense peaks for C1s and O1s levels. Besides, the SNPs' functionality was also enhanced as they displayed a two-fold increase in antibacterial activity.