Bifunctional reduced graphene oxide/polyelectrolytes/MoS2-AuNPs hybrids with Vis/NIR photocatalytic and photothermal activities for biosafe and efficient antibacterial applications

The development of bacterial resistance to antibiotics and its global spread highlights the urgent need for new alternative antimicrobial agents. Here, we have developed a biosafe antibacterial material based on reduced graphene oxide/polyelectrolytes nanolayers and gold nanoparticles functionalized molybdenum disulfide (rGP1.5/MoS2-AuNPs) via in situ synthesis and electrostatic assembly. The rGP1.5/MoS2-AuNPs has high visible and near-infrared absorption, which can efficiently provide remarkable photothermal conversion efficiency and generate reactive oxygen species (center dot O2- , center dot OH, 1O2) via photocatalytic oxygen reduction and water oxidation. The rGP1.5/MoS2-AuNPs combines the photocatalysis with photothermal effect, exhibiting a biosafe and effective killing for Gram-negative and Gram-positive bacterial. The rGP1.5/MoS2-AuNPs simultaneously optimizes three key parts for antibacterial: i) polyelectrolytes component promotes bacterial adhesion, ii) reduced graphene oxide and AuNPs components provide photothermal conversion capacity and increase light absorption, iii) MoS2 component generates photogenerated electron-hole pairs, and the electrons are rapidly conducted from the AuNPs to the reactants, which promotes the rapid separation of the electron-hole pairs, resulting in the generation of reactive oxygen species. This work provides a simple but powerful way to prepare photocatalytic and photothermal material for antibacterial applications.