Preparation of Hybrid Gold/Polymer Nanocomposites and Their Application in a Controlled Antibacterial Assay

In this work, we report a photosensitizer-loaded hybrid nanostructure that shows high antibacterial efficiency after surface interaction with a lectin protein. Gold nanoparticles were generated on the polymer nanoparticle surface through an in situ reduction method and behaved as a plasmonic amplifier. After conjugation of the photosensitizer rose bengal onto the hybrid nanoparticles, higher phosphorescence intensity and generation of reactive oxygen species (ROS) were observed. The nanocomposites showed high antibacterial efficiency toward Gram-negative Escherichia coli treated with a lectin protein concanavalin A, which caused self-assembly of the bacteria and nanoparticles. Therefore, the as-prepared nanostructure considerably improved the effectiveness of ROS toward bacteria and provides an alternative strategy for controlled antibacterial assays.