A Highly Sensitive O2•- Biosensor Based on PEDOT:PSS/SA Composite Conductive Hydrogel

Superoxide anion (O-2(center dot-)) plays a vital role in the pathogenesis of many diseases, making it a biomarker of great value in early assessment of disease progression. However, due its short half-life, low concentration and rapid fluctuations, detecting O-2(center dot-) poses significant challenges. In this study, we proposed an electrochemical biosensor based on a composite conductive hydrogel that enabled rapid and sensitive O-2(center dot-) detection. The hydrogel synthesized with poly (3,4-ethylenedioxythiophene) : poly (styrenesulfonate) (PEDPT:PSS) and sodium alginate (SA) exhibited good conductivity and mechanical properties. When applied for O-2(center dot-) detection, the composite conductive hydrogel-based biosensor showed a linear range of 0.011 similar to 32.59 mu M, a sensitivity of 9.383 mu A mu M-1 cm(-2) and a detection limit of 0.007 mu M, with robust anti-interference capabilities and stability. This innovative O-2(center dot-) biosensor achieved high responsiveness at low concentrations and held promise for advancing O-2(center dot-) detection and facilitating early disease diagnosis.