Tuning conductivity and roughness of diselenide polymer dot-coated surface for ROS-mediated selective real-time wireless detection of cancer cells

Reactive oxygen species (ROS)-responsive materials for the selective and sensitive electrochemical detection of cancer cells have been studied comprehensively, especially owing to the variable concentration of H2O2 in normal and tumor cells. In this report, we develop a real-time electrochemical sensor based on diselenidefunctionalized dopamine-conjugated hyaluronic acid polymer dots (PD(HA/DP)-DiSe) nanoparticles coated on a substrate that could be used for selective tumor diagnosis by tuning the coated surface morphology. The hyaluronic acid-based cancer cell-targeted PD(HA/DP)-DiSe-coated surface demonstrates selectivity and sensitivity toward ROS because of the change in the optical fluorescence after treatment. Owing to cleavage of the Se-Se bond and the formation -Se-OH/-Se-OOH, the PD(HA/DP)-DiSe coated-surface is tuned from a sphere-like to a sheet-like form with smaller size changing the electronic impedance of the sensor. A real-time in vitro selective diagnosis conducts by connecting the sensor to the wireless system and produces an accurate result to distinguish different ratios of MDCK:MDA-MB-231 and MDCK:HeLa cells. Finally, the developed ROS-responsive sensor could specifically differentiate the cancer microenvironment, which is helpful for advanced and selective biomedical purposes.