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.

Selenium Nanoparticles for Antioxidant Activity and Selenium Enrichment in Plants

“…Initially, the bulk selenium powder was dissolved in EDA by heating the mixture at 120 °C for 3 h, resulting in a homogeneous black Se−EDA solution. This dissolution is similar to how elemental sulfur can be dissolved in EDA by forming an open-chain alkylammonium polyselenide, 34,36,37 as shown in eq 4.…”

“…Initially, the bulk selenium powder was dissolved in EDA by heating the mixture at 120 °C for 3 h, resulting in a homogeneous black Se–EDA solution. This dissolution is similar to how elemental sulfur can be dissolved in EDA by forming an open-chain alkylammonium polyselenide, ,, as shown in eq . 2 normalH 2 NCH 2 CH 2 NH 2 + normalSe x → false( normalH 2 normalNCH 2 CH 2 normalNH 3 + false) false( normalH 2 NCH 2 CH 2 NH−Se x − ) …”

“…The scavenging capability of SeNPs toward ABTS free radicals was assessed according to the literature . Typically, 38 mg of ABTS and 3.3 mg of K 2 S 2 O 8 were dissolved in 5 mL of PBS solution separately.…”

“…The scavenging capability of SeNPs toward ABTS free radicals was assessed according to the literature. 34 Typically, 38 mg of ABTS and 3.3 mg of K 2 S 2 O 8 were dissolved in 5 mL of PBS solution separately. These solutions were then combined and allowed to react in a dark environment for 16 h, resulting in the formation of ABTS free radical solution.…”