Environmentally friendly production, characterization, and evaluation of ZnO NPs from Bixa orellana leaf extract and assessment of its antimicrobial activity

Zinc oxide nanoparticles (ZnO NPs) are establishing themselves as an important class of nanomaterials due to their exceptional physicochemical properties and wide range of applications. Due to their affordability, lack of toxicity, and strong biocompatibility, ZnO NPs find extensive use in the field of biomedicine. ZnO NPs are promising in biomedicine, especially for their ability as anticancer and antimicrobial agents. The ecologically sustainable preparation of metallic NPs using different plant extracts is a viable alternative to more conventional synthesis methods. The present study investigates the effects of changing the physical conditions on ZnO NPs synthesis from Bixa orellana (B. orellana) extract using the precipitation method. Confirmation and characterization of the ZnO NPs were achieved by analytical techniques. EDS results verified that highly pure ZnO NPs were synthesized. X-ray diffraction analysis verified the crystal nature of the synthesized NPs and their crystalline particle size of 82.66 nm. The XRD graphs strongly indicate the formation of wurtzite ZnO due to the presence of the (100), (002), and (101) planes. The antibacterial activity was assessed through the utilization of agar disc diffusion. The findings revealed that ZnO NPs exhibited significant efficacy in inhibiting the growth of both Gram-positive and Gram-negative bacteria. The zone of inhibition with the greatest diameter (22 mm) was reported for the bacterial strain B. cereus. The present investigation provides evidence that B. orellana leaves extract is capable of producing ZnO NPs, which play a crucial role in its antibacterial action. Additional investigation is necessary to validate the role of diverse phytochemicals in the synthesis of ZnO NPs and their applications in diverse fields such as agriculture, cosmetics, food, and healthcare.