Crystallographic analysis of silk sericin-stabilized zinc oxide nanoparticles with enhanced antimicrobial and photocatalytic properties

The use of bio-stabilizers in nanoparticle synthesis has attracted considerable interest because of their environmentally friendly and sustainable characteristics. In this study, silk sericin was utilized as a bio-stabilizer for synthesizing zinc oxide nanoparticles (ZnO NPs). The silk sericin-stabilized zinc oxide nanoparticles (SS-ZnO NPs) were analyzed using X-ray Diffraction (XRD), UV–Vis spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray Spectroscopy (EDS). XRD confirmed a hexagonal wurtzite structure with an average crystallite size of 11.02 nm. UV–Vis spectroscopy showed a distinct absorption peak at 380.0 nm and an optical band gap of 3.23 eV, while the FTIR peak at 448.0 cm⁻¹ corresponds to Zn–O stretching, indicating the presence of ZnO NPs. EDS analysis confirmed the mass percentages of Zn and O as 85.08 % and 14.92 %, respectively. SEM revealed a uniform spherical morphology with an average diameter of 32.48 nm. The photocatalytic activity of SS-ZnO NPs was evaluated using methylene blue dye, demonstrating superior degradation compared to uncapped ZnO. Additionally, the nanoparticles exhibited strong antibacterial activity against drug-resistant gram-positive Staphylococcus aureus and gram-negative Escherichia coli. The findings confirm that silk sericin-stabilized ZnO NPs possess excellent photocatalytic and antibacterial properties, making them promising candidates for environmental remediation and antibacterial applications, particularly in combating water pollution and drug-resistant pathogens.