Fabrication of AgBr nanomaterials as excellent antibacterial agents

Abstract

Nanoparticles of a sparingly soluble silver salt of AgBr with an appropriate solubility product and high photocatalytic response ought to be promising candidates with superior and multifunctional antibacterial effects, but they have received relatively little scientific attention until now. In the present study, the antibacterial activities of AgBr nanocubes and their derivative Ag@AgBr against E. coli were investigated both in the dark and under visible light irradiation. Benefiting from the “dual-punch” of eluted Ag⁺-induced disturbance of bio-function and nanocube-induced contact damage to cellular membranes, the 100 nm well-defined AgBr nanocubes realized outstanding antibacterial properties, with MIC (minimal inhibition concentration) and MBC (minimum bactericidal concentration) values as low as 0.1 μg ml⁻¹ and 0.4 μg ml⁻¹, respectively. Ag decoration on the surface of AgBr seems to deteriorate the antibacterial properties, as the MIC and MBC values increased to 0.75 μg ml⁻¹ and 1 μg ml⁻¹ in the dark for the sample of Ag@AgBr, but it exhibits better photocatalytic inhibition of E. coli growth than pure AgBr by virtue of the enhanced light-harvesting by the LSPR effect from the Ag component. Thus, the encouraging results shown in this study indicate the great potential of AgBr nanomaterial to serve as an antibacterial candidate with high antibacterial activity.