A newly synthesized Au/GO-Co3O4 composite effectively inhibits the replication of tetracycline resistance gene in water

A novel Au-graphene oxide (GO)-Co3O4 hollow sphere (Au/GO-Co3O4) was synthesized and its potential in binding with antibiotic resistance genes (ARGs) and inhibiting their replication was examined in this study. Tetracycline-resistant genes (tetA) with two amplicon lengths were selected as the model ARGs due to its highly detected in the environment. The Au/GO-Co3O4 composite was synthesized using tetra-n-butylammonium bromide (TBAB) as a mediating proxy. We found that it could bind with tetA and consequently inhibit its replication to a greater extent compared with pure Co3O4 and GO-Co3O4 hybrid. Furthermore, the Au-GO-Co3O4 composite was more efficient in binding with short fragments of tetA-ARGs (S-tetA) than long fragments (L-tetA). The interaction mechanism between the composite and tetA was systematically analyzed using spectra methods (FTIR, Raman, UV-Vis, and fluorimetric spectra), isolated filtrate assays, and gel electrophoresis. It is found that the adsorption of both GO and gold nanoparticles for tetA as well as cleavage effect of cobalt oxide/cobalt ions played a critical role in the capture and damage of tetA. Furthermore, we found that the interaction of both Co3O4 and GO-Co3O4 with tetA was mainly through intercalation mechanism, however, that of Au/GO-Co3O4 with tetA was mainly through groove binding mechanism. These findings in this study throw light on the new approaches for purification of ARGs contaminated water and elimination of antibiotic resistance of ARGs by novel inhibitor.