A facile one-pot method to two kinds of graphene oxide-based hydrogels with broad-spectrum antimicrobial properties

• Two kinds of GO-based hydrogels (BKB/GOG and BKB/PDA/rGOG) were synthesized.
• The swelling degrees of the GO-based xerogels were calculated.
• Antibacterial experiments were conducted to measure the antibacterial properties.
• The bacterial kinetic test was studied to evaluate the antibacterial activity.

Graphene oxide (GO) has immense potential applications in water purification and biomedical field. Recently, three-dimensional GO-based hydrogels have attracted great attention owing to their advantageous properties. However, it is quite difficult to develop highly efficient, low cost, broad spectrum antibacterial materials that can be easily recycled. In this experimental work, we used a facile one-pot method to synthesize two kinds of GO-based hydrogels: benzalkonium bromide/graphene oxide hydrogel (BKB/GOG) and benzalkonium bromide/polydopamine/reduced graphene oxide hydrogel (BKB/PDA/rGOG). The as-prepared three-dimensional hydrogels were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), and Raman spectroscopy. The swelling degrees of BKB/GO xerogels and BKB/PDA/GO xerogels with different BKB concentrations were calculated. The maximum value of swelling degree was found to be 95.2 mg/mg. Owing to the synergistic effect of graphene oxide and benzalkonium bromide, the resultant hydrogels exhibited strong antibacterial activities against both Gram-negative and Gram-positive bacteria. The result of bacterial kinetic tests agreed well with that of the qualitative antibacterial experiments. The resultant hydrogels could be easily removed from the solution, which enhanced their potential use in industrial applications. The antibacterial effect of the hydrogel synthesized from benzalkonium chloride (BKC) and graphene oxide was investigated. The findings of this investigation can be beneficial in elucidating the mechanism of synthesis process that involves benzalkonium salts and graphene oxide.