Green synthesis, morphological characterization, antimicrobial, antioxidant, biomolecular interaction of manganese dioxide nanoparticles using Terminalia catappa Leaf Extract

The green synthesis of manganese dioxide nanoparticles (TC-MDO NPs) using Terminalia catappa (T. catappa) leaf extract is presented in this work in an effective and environmentally friendly manner. Different spectroscopic methods, including UV–visible, FT-IR, Powder XRD, EDX, SEM and TEM were used to characterise the synthesised TC-MDO NPs. The effective synthesis of TC-MDO NPs was confirmed from the UV-visible and FT-IR spectroscopic, Powder XRD and EDX methods. The rectangle shape was validated by the results of the SEM and TEM techniques with an average particle size of 13–18 nm. The agar diffusion method was used to investigate the antibacterial and antifungal activities of TC-MDO NPs, while the DPPH radical scavenging assay was used to determine their antioxidant capabilities. These findings point to better antioxidant and antimicrobial potential. To thoroughly investigate the biointerfacial interaction between DNA/BSA with TC-MDO NPs at varied DNA/BSA concentrations, UV–vis absorption spectra and fluorescence spectra are used. When DNA and BSA come into contact with nanoparticles, there are noticeable structural and conformational changes, according to physicochemical investigations of TC-MDO NPs. Green synthesis appears to offer a cost-effective, environmentally friendly and simple alternative to traditional ways of producing TC-MDO NPs. The strong bioactivity exhibited by the produced TC-MDO NPs suggests therapeutic usage as an antibacterial and antioxidant. Regarding correlation, all investigations indicated that intercalative contact controls the majority of the interaction between nanoparticles and DNA. The findings provide critical fundamental understanding into the study of DNA and TC-MDO NPs. Biosensing, bioimaging, and therapeutic applications all depend on DNA's ability to bind to TC-MDO NPs.