Quaternary ammonium salt-based cross-linked micelle with copper nanoparticles for treatment of sulfate reducing bacteria biofilm

Abstract

Sulfate reducing bacteria (SRB) biofilm was the main cause of metal corrosion. However, at present, most antibacterial agents could only effectively kill SRB bacteria, but had nothing to do with its biofilm, as they could hardly penetrate extracellular polymeric substance on the surface of biofilm. Herein, we reported a novel quaternary ammonium salt-based cross-linked micelle with copper nanoparticles (Cu@QAS@CM nanoparticle) for removing SRB biofilm to resist metal corrosion. The Cu@QAS@CM nanoparticle could effectively adsorb on the surface of SRB biofilm because of its positive electricity, then penetrate and diffuse into whole biofilm in the form of nanoparticles. After entering the biofilm, the Cu@QAS@CM nanoparticle was dissociated into Cu and QAS fragments in the acidic environment inside the SRB biofilm due to its pH responsiveness. The QAS fragments could efficiently kill the living bacteria in the SRB biofilm, while copper can affect the mass transfer process of the biofilm, which can synergistically and efficiently remove the SRB biofilm. Hence, the Cu@QAS@CM nanoparticle holds great potential in replacement of traditional antibiotics to treat treating corrosion persistent infection cause by biofilms.