Bio-inspired synthesis of CdO nanoparticles using Citrus limettapeel extract and their diverse biomedical applications

Nowadays, the green chemistry approach for nanoparticle (NP) synthesis has acquired a plethora of interest due to its expeditious and eco-benevolent nature. In the current study, Citrus limettapeel extract was applied as a unique natural reducing/stabilizing agent in the bio-inspired fabrication of cadmium oxide (CdO) NPs. The physicochemical features of the prepared CdO NPs were critically studied through XRD, FTIR, SEM, EDX, HRTEM, PL, and UV-DRS analyses. According to XRD examination, the CdO NPs were confirmed to have a single face-centred cubic Monteponite phase. The median particle size of CdO NPs was revealed by HRTEM investigation to be 51.5nm, and the XRD study confirmed this finding. The UV-DRS was utilized to calculate the band gap of bio-fabricated NPs and was found to be 2.6eV. FTIR analysis evinced the functional groups of biologically active molecules of Citrus limettapeel extract. Moreover, diverse biological applications such as antibacterial, antioxidant, anticancer, DNA damage, and biocompatibility studies of Citrus limettapeel extract-mediated CdO NPs were revealed. The antibacterial efficacy of the CdO NPs screened against human pathogens (B. subtilis, E. coli, K. pneumoniae, and S. typhi) and displayed higher bactericidal performance against B. subtilis. The CdO NPs displayed dose-dependent anticancer performance against the cancer cell line (A-549) in the MTT assay, with activity at an IC50of 152.2μg/mL. The DPPH and ABTS assays were applied to determine the antioxidant capacity of CdO NPs. For the DPPH and ABTS assays, the IC50values of CdO NPs were determined to be 94.47 and 68.98μg/mL, respectively. Additionally, Citrus limettapeel extract-mediated CdO NPs also displayed DNA damage and biocompatibility performance. Therefore, due to their biological functionality, these biogenically produced NPs perform as efficacious therapeutic agents.