Facile synthesis and characterization of green synthesized MnO2 nanoparticles for their photocatalytic, bovine serum albumin interaction and in vitro anticancer activities

Abstract

Recently, scientists have become interested in the biosynthesis of nanoparticles due to the need to develop new synthesis methods that are cost-effective, safe, and efficient. In this research, MnO₂ nanoparticles (MnO₂ NPs) were biosynthesized using Pongamia pinnata (PP) extract, a natural, non-toxic hydrocolloid. These PP-MnO₂ NPs were then investigated for their potential use in dye degradation, BSA binding, and anticancer activity. The nanoparticles were characterized through techniques such as XRD, HR-TEM, FESEM-EDS, UV-DRS, EIS, and FTIR spectroscopy. XRD analysis, using the Debye–Scherrer formula, indicated that the average crystallite size was 48 nm. UV-Visible spectrum showed optical absorption properties at 374 nm, while HR-TEM imaging provided details on the morphology of the nanoparticles. EDX analysis confirmed the purity of the samples. In the FTIR spectra, metal-oxygen stretching and bending modes of vibrations were observed. The photocatalytic degradation of hazardous methylene blue (MB) dye using PP-MnO₂ NPs under visible-light irradiation demonstrated a degradation efficiency of 80.34%. The in vitro anti-cancer activity of the synthesized material was assessed against human cancer cell lines, namely, MCF-7, HepG2, and HeLa. The results showed that PP-MnO₂ NPs possess significant cytotoxicity against selected human cancer cell lines. Interactions between the synthesized PP-MnO₂ NPs and BSA were also evaluated. The spectrophotometric and fluorometric analyses showed a gradual reduction in peak intensities and shifts in wavelengths, indicating binding affinity between the PP-MnO₂ NPs and the biomolecules.