HKUST-1 loaded few-layer Ti₃C₂T for synergistic chemo-photothermal effects to enhance antibacterial activity

The drug resistance of bacteria seriously reduces the recovery rate of general disease and endangers human health. Consequently, it is urgent to investigate a non-antibiotic antibacterial material. Recently, two-dimensional MXene has shown good antibacterial properties and received extensive attention due to the large number of active sites, extremely high thermal conversion efficiency, excellent cytocompatibility and ability to penetrate pellicula. However, the antibacterial activity of Ti₃C₂T is greatly affected by the morphology and concentration. Herein, an organic-inorganic hybrid of HKUST-1@Ti₃C₂T with high specific surface area and photothermal effect was designed and fabricated. By adjusting the content of Cu(CO₂CH₃)₂·H₂O and 1,3,5-benzenetricarboxylic acid, the photothermal properties of the material can be adjusted, and the release of Cu²⁺ can be easily reduced. The morphological characterization and fluorescent staining of bacteria which were co-incubated with HKUST-1@Ti₃C₂T confirmed that Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) had adhered to the material. NIR irradiation has enabled induced hyperthermia and the release of Cu²⁺ ions, causing the disruption of the bacterial membrane, resulting in cytoplasmic leakage. Furthermore, HKUST-1@Ti₃C₂T with synergistic antibacterial effect not only exhibits an excellent bactericidal rate (over 99%) but also greatly improves cytocompatibility with the reduction of the Cu²⁺ ion release. Therefore, organic-inorganic composites have potential for synergistic effects and non-antibiotic antibacterial activity.