Click synthesis of quaternized poly(dimethylaminoethyl methacrylate) functionalized graphene oxide with improved antibacterial and antifouling ability

Abstract

A quaternized poly(dimethylaminoethyl methacrylate) functionalized graphene oxide (GO–QPDMAEMA) was successfully prepared in this study via click chemistry. Alkyne-functionalized graphene oxide (GO–alkyne) was first synthesized through a two-step amidation reaction of GO–COOH. Meanwhile, azide-terminated poly(dimethylaminoethyl methacrylate) (PDMAEMA–N3) was prepared via the atom-transfer radical-polymerization of dimethylaminoethyl methacrylate (DMAEMA). Subsequently, PDMAEMA–N3 was grafted onto the GO–alkyne through click chemistry to obtain PDMAEMA modified graphene oxide (GO–PDMAEMA). Finally, the tertiary amino groups of GO–PDMAEMA were quaternized by ethyl bromide to provide a quaternized poly(dimethylaminoethyl methacrylate) functionalized graphene oxide (GO–QPDMAEMA). Various characterization techniques, including Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV–vis spectrometry, ζ potential, Raman, contact angle analyses and field emission scanning electron microscope were used to ascertain the successful preparation of the quaternized GO–QPDMAEMA. Furthermore, antibacterial and antifouling activities of GO–QPDMAEMA were investigated via protein adsorption, as well as bacterial and cell adhesion studies. The results suggest that the GO–QPDMAEMA surface exhibited significant antibacterial and antifouling properties, compared with the GO–COOH and GO–PDMAEMA surfaces.