Biosynthesis and Optimization of ZnO Nanoparticles Using Ocimum lamifolium Leaf Extract for Electrochemical Sensor and Antibacterial Activity

In this study, zinc oxide nanoparticles (ZnO NPs) weresynthesizedusing an aqueous extract of the Ocimum lamifolium (O. lamifolium) plant. The I-optimal coordinateexchange randomized response surface methodology (RSM) was used tooptimize the effect of the zinc acetate precursor, temperature, andtime on ZnO NPs by designing nine runs. From ANOVA analysis, the significanceand validity of the designed model showed that the optimal valuesof the zinc acetate precursor, temperature, and time during ZnO NPssynthesis were found to be & SIM;0.06 M, & SIM;30 & DEG;C, and & SIM;1.35 h, respectively. The obtained ZnO NPs under these optimizedconditions were characterized and explored by UV-vis, TGA/DTA,FTIR, XRD, SEM-EDX, TEM, HRTEM, and SAED. Furthermore, the electrocatalyticperformance of ZnO NPs was performed for sulfamethoxazole (SMZ) sensingactivity with a 0.3528 & mu;M (S/N = 3) limit of detection (LOD).In addition, an antibacterial study revealed that ZnO NPs confirmedan excellent zone of inhibition against E. coli, S. aureus, P. aeruginosa, and S.pyogen pathogenic drug resistance bacterial strains at concentrationsof 50, 75, and 100 & mu;g/mL. Thus, ZnO NPs synthesized using the O. lamifolium leaf have a potential electrocatalytic activityfor diverse organic pollutant detection as well as a desirable materialfor such drug resistance antimicrobial strains.