Hydrothermally synthesized silver-decorated propolis quantum dots: a dual-action antibacterial and antioxidant nanocomposite

Propolis carbon quantum dots (PCQDs) and silver nanoparticles (AgNPs) were hydrothermally synthesized. The PCQD@Ag nanocomposite was formed by reducing silver nitrate (AgNO3) with sodium citrate. PCQDs and AgNPs were characterized by UV spectroscopy, photoluminescence (PL) spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), and Transmission Electron Microscopy (TEM). In addition, X-ray diffraction (XRD) was also performed on AgNPs. The antioxidant activities of AgNPs, PCQDs, and PCQDs@AgNPs were also studied. Furthermore, their antibacterial activities were investigated under fluorescent light by comparing bacterial strains isolated from periodontal abscesses. It was observed that PCQDs and AgNPs had dimensions of 8–10 nm and 20–35 nm, respectively, and PCQDs exhibited a strong fluorescence peak around 380 nm. PCQDs were found to be a potent photosensitizer. PCQDs, AgNPs, and PCQD@AgNPs exhibited antibacterial activity against periodontal abscess-causing bacteria and demonstrated strong antioxidant activity.