Conductive, physiologically responsive hydrogels.

Coupling molecular sensing with electrical conductivity may provide an important and valuable resource in assessing disease pathology. Here, we introduce pH-responsive hydrogels with homogeneously synthesized gold (Au) nanoparticles that reversibly alter conductivity through pH-induced volumetric swelling. These intelligent hybrid materials respond to physiological pH shifts (pH 7.4 to 5.5) that can (1) alter the conductivity of the gel or (2) create conductive conduits via micropatterned arrays.