Biogenic Luminescent Zinc Oxide Nanoparticles From <scp> <i>Centratherum punctatum</i> </scp> : Their Synthesis Optimization Through Box–Behnken Design and Its Antimicrobial Property and Photocatalytic Dye Degradation

The current study utilizes Box-Behnken design (BBD) to optimize zinc oxide (ZnO) nanoparticles biogenic synthesis from Centratherum punctatum leaf extract. The study also explores the biogenically generated zinc oxide nanoparticles from C. punctatum at optimized conditions evaluated for anti-oxidant, antimicrobial, and photocatalytic dye degradation properties. Optimized parametric conditions for zinc oxide nanoparticles from C. punctatum were zinc nitrate (50 mM), incubation time (24 h), temperature (75°C), and pH (8). Biogenic ZnO NP characterization revealed that hexagonal wurtzite morphology was 50-70 nm in size, showing characteristic absorption at 302 nm. Further, biogenically synthesized zinc oxide nanoparticles from C. punctatum screened for anti-oxidant properties using the DPPH spectrophotometric method revealed that ZnO NP possesses an equipotent IC₅₀ value as the reference standard compared with the C. punctatum plant leaf extract IC₅₀ value. Antimicrobial screening of ZnO NP shows its maximal zone of inhibition against clinical pathogens compared with standard tetracycline antibiotic. ZnO NP showed 94% degradation efficiency for rhodamine B dye under photocatalytic degradation condition in 100 min incubation. Biogenically synthesized ZnO nanoparticles from C. punctatum leaf extract showed excellent antimicrobial and photocatalytic dye degradation useful for both medical and environmental applications.