Cancer intra and extracellular microenvironment-responsive electrical signal of touchable conductive hydrogel

A wireless-integrated tumor microenvironment-responsive sensor designed from diselenide-functionalized carbon dot (dsCD) and hyaluronic acid polymer dot (PD(HA)) loaded in a mineralized conductive hydrogel (dsCD-PD(HA) Hydrogel) for detecting cellular reactive oxygen species (ROS) and pH detection. The manufactured ROS/pH responsive conductive hydrogel efficiently differentiated between cancer cells and normal cells in response to cellular factors through changes in fluorescence, electrical and mechanical response. Tumor microenvironment acidity and high ROS concentrations caused fluorescence recovery boronate ester and diselenide bond cleavage alongside a change in electrical resistivity from 78.9 kΩ (pH 7.4) to 38.8 kΩ (0.1 mM HO/pH 6.8) due to disintegration of molecular interaction in the sensor. In vitro electrochemical analysis revealed different ΔR/R bending profiles between cancer (26.2 % and 25.9 % for HeLa and PC-3, respectively) and normal cells (17.9 %), alongside the optical performance demonstrating higher regain of fluorescence of cancer cells (HeLa and PC-3) compared to the normal cells (CHO-K1). Additionally, the dsCD-PD(HA) Hydrogel demonstrated favorable biocompatibility and ROS scavenging, with selective targeting of cancer cells. A wireless sensing platform was developed by connecting the dsCD-PD(HA) Hydrogel sensor to a smartphone, showing a precise signal during detection resistance or electro-mechanical signals.