Achieving high bactericidal and antibiofouling activities of 2D titanium carbide (Ti ₃ C ₂ T _x ) by delamination and intercalation

Abstract

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 (Ti 3 C 2 T x ), and its bactericidal mechanism was interpreted. The delaminations and intercalations all significantly increased the colloidal stability and bactericidal effect of Ti 3 C 2 T x 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 Ti 3 C 2 T x . The application of Ti 3 C 2 T x -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 Ti 3 C 2 T x -based antimicrobial surface coatings and increases their bioapplication potential.

Dispersibility and Photochemical Stability of Delaminated MXene Flakes in Water

“…Linear correlation analysis of predefined concentration-dependent optical absorbance (800 nm) was applied to estimate the concentration of delaminated Ti 3 C 2 T x suspensions ( Figure S8, Supporting Information). [60] The initial concentrations of delaminated Ti 3 C 2 T x suspensions were 115 ± 21, 154 ± 32, and 143 ± 26 mg L −1 for H 2 O-Ti 3 C 2 , HMH-Ti 3 C 2 , and KOH-Ti 3 C 2 , respectively.…”

“…Preparation of Ti 3 C 2 T x Flakes: The Ti 3 C 2 T x flakes were synthesized following the same method as described in our previous papers. [60,61] Briefly, the initial bulk Ti 3 C 2 T x powders were prepared by etching 5wt% MAX in 49% HF at 50 °C for 36 h. The obtained powders were washed with ultrapure water and centrifuged several times until the pH of the supernatant reached 5-6. The dispersion was filtrated through a PVDF membrane and then transferred to a vacuum desiccator overnight.…”

“…[20,59] The (002) peak of HMH-Ti 3 C 2 and KOH-Ti 3 C 2 shifts to lower angles than that of H 2 O-Ti 3 C 2 , indicating their better intercalation and exfoliation effects. [60] Other XRD peaks at 18.4°, 27.9°, 35.1°, 43.3°, 52.6°, 57.4°, 60.5°, and 68.3° are also assigned to Ti 3 C 2 T x . [1,61] For the Raman spectra ( Figure 2C), the peaks at 205, 375, and 605 cm −1 are assigned to TiC vibrations.…”

Characterization and Application of PVDF and Its Copolymer Films Prepared by Spin-Coating and Langmuir–Blodgett Method

“…As a biocompatible material with excellent chemical stability, PVDF is useful in many medical applications that can take advantage of the pyroelectricity and piezoelectricity of PVDF and its copolymers, including human physiological signals detection [214][215][216][217], tissue engineering scaffolds [218][219][220][221][222][223], and antifouling ultrafiltration membranes [224][225][226][227][228].…”

“…The membrane showed high permeability, with superior retention properties to humic acid [224]. Rajavel et al prepared Ti 3 C 2 Tx-coated PVDF membranes that could effectively inactivate Escherichia coli, thus preventing biofilm formation on the active membrane surfaces and showing high potential for antibiofouling [227].…”