Cancer cells targeting H2O2-responsive MXene-integrated hyaluronic acid polymer dots coated sensor

Abstract

We successfully developed a reactive oxygen species (ROS)-responsive electrochemical sensor based on a substrate coated with cancer cell-targeted hyaluronic acid polymer dot-integrated ROS-degradable MXene particles [MXene-PD(HA)] for identifying cancer conditions in vitro. Exposure to high H2O2 concentration of cancer cells selectively controls the electroconductivity and photothermal conversion of the MXene-PD(HA) due to the involvement of oxidation reaction, changing MXene into TiO2. The resistance of the sensor increases with accumulation of H2O2, elevating the resistance from 225.4 ± 62.39 kΩ (0 mM) to 3418 ± 39.22 kΩ after treatment with 1 mM H2O2. In vitro treatment with CHO-K1 and HeLa cells adjusted the morphology of MXene-PD(HA)-coated surfaces and electrochemical sensing performance through the degradation of MXene by intracellular ROS. The sensor could differentiate normal and cancer cells by displaying an increase in resistance from 147.4 ± 16.00 kΩ (control) to 994.4 ± 152.6 kΩ (CHO-K1) and 2040 ± 460.1 kΩ (HeLa). Besides, the MXene-PD(HA) is uptaken after 1 h treatment for CHO-K1 cells and as early as 0.5 h for HeLa, displaying a rapid detection. In conclusion, the MXene-PD(HA) electrode exhibited the ability to distinguish between normal and cancer cells and showed promising potential for the detection of tumor microenvironment.