Assessment of oxygenated polycyclic aromatic hydrocarbon cytotoxicity using TiO2-MXene/MWCNTs/PDA/GCE electrochemical sensor

Oxygenated polycyclic aromatic hydrocarbons (OPAHs) present in the environment can enter the skin through direct contact and long-term exposure can increase the risk of skin inflammation, allergic reactions and skin cancer. In this study, a titanium dioxide-two-dimensional transition metal carbide/multi-walled carbon nanotubes/polydopamine/glassy carbon electrode (TiO2-MXene/MWCNTs/PDA/GCE) electrochemical biosensor was prepared to evaluate the cytotoxicity of OPAHs based on the changes in the content of xanthine/guanine (X/G) during cellular metabolism. The TiO2-MXene/MWCNTs/PDA/GCE exhibited excellent electrocatalytic activity and sensitivity. The surface morphology, structure and electrochemical properties of TiO2-MXene/MWCNTs/PDA composite material were characterized using scanning electron microscopy, X-ray diffraction and cyclic voltammetry. Human skin fibroblast cells (HFF-1) were used as model cells, and the cell viability was evaluated based on the electrochemical signal changes of X/G. When exposed to OPAHs for 30 h, the half-maximal inhibitory concentrations (IC50) of 1,4-benzoquinone (1,4-BQ), 1,2-naphthoquinone (1,2-NQ), and 9,10-phenanthrenequinone (9,10-PQ) on HFF-1 cells were 291.88, 67.72, and 4.44 µmol·L−1, respectively, which were lower than the IC50 values of 1075.51, 113.96, and 9.63 µmol·L−1 obtained using the traditional MTT assay, indicating higher sensitivity of the sensor. This study achieved sensitive detection of purines in HFF-1 cells, providing a technical method for evaluating the cytotoxicity of persistent organic pollutants OPAHs in the environment.