Synthesis and bacterial inhibition of novel Ag 2 S–N–CQD composite material

The present work aims to combine carbon quantum dots (CQDs) with the good water solubility, biocompatibility, and low toxicity and nano-sized silver sulfide with excellent antibacterial effect in the synthesized composite. The composite was further treated with polyethyleneimine (PEI) and conjugated with graphene oxide (GO). The as-prepared composite Ag 2 S–CQDs–PEI–GO exhibits a core of Ag 2 S with the size of 20–50 nm and the shell of CQDs with the average particle size of 1.8 nm. The core shell structure is loaded on the template of PEI–GO. Strong antibacterial effect was observed on Ag 2 S–CQDs composite against four strands of bacteria Staphylococcus aureus ( S. aureus ), Escherichia coli ( E. coli ), Enterococcus faecalis ( E. faecalis ), and Pseudomonas aeruginosa ( P. aeruginosa ). We briefly discussed the bacteriostatic mechanism of the composite. The as-prepared composite has huge potential in the development of biomedicine.