Evaluation of Bioactive Potential of a Tragia involucrata Healthy Leaf Extract @ ZnO Nanoparticles

The aim of the present work is to prepare ZnO nanoparticles (NPs) from Tragia involucrata leaf extract by low-cost technology. The extracted ZnO NPs were calcined at different temperatures such as 400 °C (TZ 1), 450 °C (TZ 2), and 500 °C (TZ 3). The as-prepared ZnO NPs were characterized using techniques such as TG-DTA, XRD, FTIR, and SEM. Based on the observations made using the above techniques, the calcination temperature was fixed at 450 °C and EDS, HR-TEM, and VSM studies were made for these samples. The XRD analysis revealed the hexagonal structure with the average crystallite size being ~ 27 nm for the different samples (TZ 1, TZ 2, and TZ 3). The occurrence of FTIR peaks in the region 600–450 cm−1 confirmed the presence of the Zn–O bond. SEM and HR-TEM images indicated the rod and conical shapes for the bio-synthesized ZnO NPs, and the d-spacing value has been found to be 0.24 nm with (1 0 1) lattice plane, matching very well with that of XRD. The SAED pattern clearly portrayed annular rings indicating the single crystalline nature. The results of VSM studies indicated a diamagnetic nature at room temperature. The green synthesized ZnO NPs were screened for antibacterial and antifungal activities. Among the bacteria used, Klebsiella pneumoniae has secured maximum sensitivity (22 mm) and Proteus vulgaris has secured minimum sensitivity (12 mm). In the case of fungal studies, Aspergillus niger showed a maximum sensitivity (16 mm) as compared to Aspergillus flavus (15 mm). Thus, it is concluded that the bio-synthesized ZnO NPs using Tragia involucrata leaf extract may serve as a potential candidate for biomedical applications.