Fe/ABTS/PVP nanocomplexes with dual GSH-depleting for photothermal-reinforced catalytic bacterial killing

In this study, Fe/ABTS/PVP nanocomplexes (named FAPs) as photothermal-reinforced catalytic antibacterial agents were prepared using the coordination-induced assembly of Fe (III), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and polyvinylpyrrolidone (PVP). The redox pairs of Fe(II)/Fe(III) in FAPs can catalyze the H2O2 to hydroxyl radicals (•OH) through Fenton reactions, thereby killing effect on bacteria. The photothermal effect of ABTS•+ in FAPs stimulated by near infrared (NIR) irradiation can further improve the catalytic effect, thereby generating more •OH and achieving better antibacterial activity. What's more, the reduction reaction between glutathione (GSH) and ABTS•+ results in the depletion of the GSH level, the redox pair of Fe(II)/Fe(III) is also beneficial in the consumption of GSH. This dual depletion of GSH further expands the intracellular oxidative stress. Thus, the integrated function of photothermal effect, catalytic property, and dual depletion of GSH by FAPs provides a new strategy for fighting against bacterial infections.