Synthesis and Characterization of Bimetallic Platinum/Selenium (Pt/Se) Nanoparticles for Synergistic Antibacterial Activity

We used ascorbic acid for the preparation of bimetallic platinum-selenium nanoparticles (Pt-Se NPs). The X-ray diffraction (XRD) spectra confirmed the co-existence of Pt and Se in Pt-Se NPs. The spherical-shaped Pt-Se NPs sized < 20 nm without agglomeration were evidenced transmission electron microscope (TEM). Energy dispersive spectroscopy (EDS) spectrum indicated the presence of Pt (20%) and Se (10%) in Pt-Se NPs. X-ray photoelectron spectroscopy (XPS) confirmed the heterogenous Pt-enriched Pt-Se NPs with an atomic ratio of 0.32% / 0.06% of Pt/Se. The binding energies at 54.64 eV and 71.46 eV were assigned for Se (Se3d) and Pt (Pt4f) of Pt species, respectively. The zeta size of 117.9 ± 1.8 d. nm, with a poly-dispersion index (PDI) of 0.156 and a zeta potential of -20.7 mV, were measured for Pt-Se NPs. The Fourier-transform infrared spectroscopy (FTIR) showed the peaks in Pt-Se NPs related to characteristic peaks of ascorbic acid. The Pt-Se NPs (100 µg) significantly inhibited S. enterica, E. coli, L. monocytogenes, S. aureus, and B. cereus. The hemolytic and cytotoxicity assays revealed that Pt-Se NPs (0–80 µg/mL) were non-toxic to red blood cells (RBCs) and the mouse fibroblast (NIH3T3) cell line.