Achieving high bactericidal and antibiofouling activities of 2D titanium carbide (Ti3C2Tx) by delamination and intercalation

The development of extrinsic antibacterial agents using newly identified nanoscale 2D layered transition metal carbide (MXene) was established by different delamination and intercalation approaches to explore structure-bioproperty relations. Herein, we report the potential impact of the microbial inactivation of Escherichia coli (E. coli) by delaminating (water, dimethyl sulfoxide (DMSO), and isopropylamine) and intercalating (hydrazine monohydrate (HMH), sodium hydroxide, and potassium hydroxide) of MXene (Ti3C2Tx), and its bactericidal mechanism was interpreted. The delaminations and intercalations all significantly increased the colloidal stability and bactericidal effect of Ti3C2Tx suspensions via unpacking of stacked MXene layers, among which the HMH intercalation showed the best performance. Our experimental results reveal that the mechanism of bacterial killing was primarily because of surface wrapping followed by extracellular reactive oxygen species independent oxidative stress. This study also shows that the stacked layer separation along with the surface moiety is an essential and decisive factor that determines the lethal bacterial potency of Ti3C2Tx. The application of Ti3C2Tx-coated polyvinylidene fluoride (PVDF) membranes effectively inactivates E. coli; importantly, it prevents biofilm formation on the active membrane surfaces and thus has high potential for antibiofouling. This study provides useful guidelines for the future development of Ti3C2Tx-based antimicrobial surface coatings and increases their bioapplication potential.