Programming Molecular Switches within Capacitive PEDOT:DNA Hydrogels for Deciphering Pathophysiological...

Capacitive sensing technology holds significant potential for wound management. However, conventional sensing materials remain inherently unresponsive to biomarkers, limiting their utility for deciphering pathophysiological microenvironment dynamics. This study innovates capacitive poly(3,4-ethylenedioxythiophene) (PEDOT):DNA (pDNA) hydrogels via covalent cross-linking of pDNA and poly(ethylene glycol) diglycidyl ether. Within the hydrogel matrix, pDNA comprises a metastable DNA duplex formed by a programmable biomarker-responsive nucleic acid strand and a partially complementary strand. Upon encountering stimuli, the responsive sequence undergoes a conformational change into an i-motif or aptamer structure. This dissociates the pDNA duplex and disrupts its conductive network, switching the molecular circuit from "ON" to "OFF" and decreasing hydrogel capacitance, thereby transducing biological signals into quantifiable capacitance changes. By integration of a portable capacitance detector with Bluetooth wireless transmission, real-time signals are readily relayed to smartphones for intelligent analysis, enabling tracking of pH fluctuation, inflammatory dynamics, and infection status of uninfected/infected diabetic wounds with/without therapeutic intervention.