Electrochemical, antibacterial and cytotoxicity investigations of <i>Litchi chinensis</i> mediated Mn ₃ O ₄ nanoparticles

No studies were reported earlier on Litchi chinensis mediated biosynthesis of Mn3O4 nanoparticles (NPs). We synthesized Mn3O4(aq) and Mn3O4(me) NPs by employing the aqueous and methanolic extracts, respectively of L. chinensis leaves and characterized them by XRD, FTIR, Raman spectroscopy, SEM and TGA/DSC analyses. They have shown the crystalline sizes of 17.73–21.43 nm and coupling between Mn-O stretching modes of tetrahedral and octahedral sites. The NPs were crystalline, porous and agglomerated with good thermal stabilities. The cyclic voltammetry and galvanostatic charge discharge (GCD) tests have shown a reversible electrochemical behavior with better suitability of Mn3O4(aq) for supercapacitors (specific capacitance = 42.86F F/g at 1mA current density) and Mn3O4(aq) for current storage. They displayed 22–28 mm zones of inhibition (ZOI) against Staphylococcus aureus (Gram-positive) and Proteus mirabilis (Gram-negative) as compared to ciprofloxacin (ZOI = 41–44 mm) and negligible toxic hemolytic effects (0.82–1.43% lysis) on human red blood cells.