Lignin-Derived Gold-Titanium Dioxide Nanophotocomposites as Potent Photoactivatable Probes for Microbial Inactivation.

The overuse of antibiotics has accelerated antibiotic resistance, and it is a significant global threat to public health. To combat the rising threat of drug-resistant microbes, antimicrobial photodynamic therapy (APDT) has emerged as a promising alternative therapeutic strategy. This study focuses on the synthesis of eco-friendly lignin-derived gold-titanium dioxide nanophotocomposites (L@Au-TiO2 NCs). Lignin was utilized as a sustainable precursor for the synthesis of L@Au-TiO2 NCs. The gold and TiO2 nanoparticles possess inherent photodynamic properties, and thus the developed L@Au-TiO2 NCs exhibit enhanced antimicrobial efficacy due to the synergistic combination of their attributes. The antimicrobial potential of the L@Au-TiO2 NCs was evaluated against various microbial strains (Escherichia coli, Bacillus megaterium, and Candida tropicalis) under dark and green light conditions. The outcome of this study highlights the promising potential of L@Au-TiO2 NCs for photodynamic antimicrobial applications. The L@Au-TiO2 nanophotocomposites could be explored in the fields of medicine and nanotechnology to introduce innovative ideas into the biomedical field.