Computationally validated magnesium and graphene oxide anchored SnO2 quantum dots for RhB reduction and antibacterial activity

Abstract

Developing multi-functional catalysts for wastewater purification and bactericidal inactivation is quite interesting but remains a significant challenge. Herein, varying concentrations (2 and 4 wt%) of magnesium (Mg) doped with a fixed amount of graphene oxide–stannic oxide quantum dots (GO–SnO₂ QDs) were prepared by a low temperature co-precipitation approach. This research provides dual approaches, experimental as well as theoretical, to study the properties of doping-dependent SnO₂ for rhodamine B degradation and MDR S. aureus inactivation. The addition of two-dimensional GO exposed more active sites, and Mg metal facilitates the transportation of charge carriers for catalytic and antibacterial activity. Advanced characterization confirmed the multiple phases (tetragonal, orthorhombic, and anorthic), polycrystalline behavior, high light absorption intensity, and the QD-like morphology of ternary catalysts. The combination of metal, 2D materials, and metal oxides was proven to be beneficial as they synergistically increased the catalytic activities. Among all synthesized samples, optimized 4% Mg/GO–SnO₂ revealed considerable (94.7%) rhodamine B (RhB) degradation in acidic medium. The optimized sample exhibited a 3.65 ± 0.03 mm inhibition zone towards MDR S. aureus in comparison to ciprofloxacin. Mg/GO-doped SnO₂ exhibited significant inhibitory effects on DNA gyrase and tyrosyl-tRNA synthetase (TyrRS), as corroborated by the in silico approach, indicating its potential as a therapeutic agent for bactericidal action.