Probing the biomolecular interactions of oxidized Ti3C2Tx nanosheets: How surface chemistry influences serum protein binding

Ti3C2Tx has promising applications in the biomedical field due to its biocompatibility, hydrophilicity, and antibacterial activity. However, its effects on health are still being explored. This study analyzes the interaction of bovine serum albumin (BSA) with Ti3C2Tx at different levels of oxidation. Zeta potential measurements showed that the colloidal stability of Ti3C2Tx varied with the degree of oxidation, with unoxidized Ti3C2Tx (UTi3C2Tx) being the most stable, followed by fully oxidized Ti3C2Tx (F-Ti3C2Tx) and partially oxidized Ti3C2Tx (PTi3C2Tx). UV-Vis absorption and fluorescence spectroscopy confirmed that the formation of Ti3C2Tx-BSA complexes resulted in fluorescence quenching. In addition, synchronous fluorescence spectroscopy, Fourier transform infrared spectroscopy and circular dichroism showed that the interaction between F-Ti3C2Tx and BSA altered the secondary conformation of BSA, and that U-Ti3C2Tx had a weaker effect on the conformation of BSA. Molecular docking results emphasized that hydrogen bonding is the main driving force between Ti3C2Tx and BSA.