Plant-Based Fabrication of Zinc Oxide and Copper Nanoparticles using Shorea robusta Resin: Dual Evaluation of Safety and Antimicrobial Efficacy
摘要
This study reports the green synthesis of zinc oxide (ZnO) and copper (Cu) nanoparticles (NPs) using Shorea robusta resin extract as a reducing and stabilizing agent. Optical analysis revealed characteristic absorption peak of ZnO NPs at ~ 366 nm, confirming their nanoscale nature and phase purity. Cu NPs exhibited a distinct absorption band at ~ 252 nm. Scanning electron microscopy demonstrated that ZnO NPs possess predominantly faceted cuboidal morphology with particle sizes ranging from 80 to 400 nm, whereas Cu NPs exhibit quasi-spherical to sub-angular morphology with sizes of 50–350 nm. X-ray diffraction analysis confirmed the crystalline wurtzite structure of ZnO with an average crystallite size of ~ 41.7 nm, while Cu NPs showed a face-centered cubic (FCC) structure with a crystallite size of ~ 42 nm along with minor Cu₂O phase. Nanoparticle tracking analysis indicated hydrodynamic sizes centered around ~ 120 nm for ZnO nanoparticles and a bimodal distribution (~ 100 nm and ~ 180–200 nm) for Cu nanoparticles. The synthesized nanoparticles exhibited significant antimicrobial activity, with ZnO NPs showing maximum inhibition zones of 20 mm against Pseudomonas stutzeri and 29 mm against Aspergillus flavus. Cu NPs demonstrated inhibition zones of 17 mm against Pseudomonas stutzeri and 13 mm against fungal strains. Hemocompatibility studies revealed minimal hemolysis (< 1% for ZnO and < 2% for Cu at 1000 µg/mL). Cytotoxicity analysis indicated dose-dependent effects, with ZnO NPs showing comparatively lower toxicity than Cu NPs. Overall, the results demonstrate that Shorea robusta-mediated ZnO and Cu NPs possess controlled morphology, nanoscale dimensions, strong antimicrobial efficacy, and excellent biocompatibility, making them promising candidates for biomedical applications.
Graphical Abstract