High-performance supercapacitor and antifouling biosensor based on conducting polyaniline-hyaluronic acid hydrogels

We report a polyaniline-hyaluronic acid (PANI-HA) hydrogel that combines rigid conducting polymer with flexible HA. The supramolecular assembly of PANI and HA via boronic acid bonds yields PANI-HA hydrogel with unique microstructure, electrical conductivity and hydrophilicity and exhibits excellent supercapacitor performance and electrochemical sensing for immunoglobulin G (IgG). The PANI-HA hydrogel electrode shows high specific capacitance (369 F g −1 , with 0.5 A g −1 current density) and good cycling stability (85% capacity retention after 1000 galvanostatic charge–discharge cycles). In addition, the PANI-HA hydrogel-based electrode can also be used as an electrochemical biosensor for IgG detection, and the presence of highly hydrophilic HA supports low-fouling target analysis. The modified electrode exhibits good sensitivity, wide detection range (0.1 ng mL −1 –10 μg mL −1 ), and a low detection limit (0.043 ng mL −1 ) for IgG detection. We demonstrate a strategy to fabricate supramolecular hydrogel-modified electrodes and explore their potential applications in supercapacitors and biosensors. Graphical abstract High-performance supercapacitor and antifouling biosensor were fabricated based on polyaniline-hyaluronic acid hydrogel.