One-Pot Scalable Fabrication of Chitosan-Capped Antibacterial Sulfur Nanoparticles from Elemental Sulfur

Abstract

Sulfur nanoparticles (SNPs) have shown good potential in numerous fields due to their unique composition and properties. However, the direct utilization of abundant and inexpensive elemental sulfur for the large-scale fabrication of high-quality SNPs is still in its infancy. Herein, a simple one-pot approach for the preparation of SNPs is presented, and gram-scale SNPs can be readily prepared in one batch in the laboratory. By adding elemental sulfur-ethylenediamine precursor to the acidic chitosan (CS) solution, chitosan-capped sulfur nanoparticles (CS-SNPs) can be formed immediately. Benefiting from the capping of CS, CS-SNPs simultaneously possess small and uniform size with an average diameter of 19 nm, good aqueous dispersibility and stability, and favorable antioxidant capability against 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) free radicals. Moreover, CS-SNPs also exhibit fine antibacterial activity against Staphylococcus aureus, and the minimum and optimal inhibitory concentrations are 256 and 512 µg mL−1, respectively. Considering the easy fabrication process and attractive attributes of CS-SNPs, this investigation not only offers an effective method for the scalable fabrication of robust SNPs but also provides a feasible way for the value-added utilization of elemental sulfur.