Electrochemical investigation for enhancing cellular antioxidant defense system based on a superoxide anion sensor

The dynamic balance of the redox system in living organisms can be disrupted by excessive superoxide anion (O2•−), which would lead to oxidative stress and induce a variety of diseases. In this case, the antioxidant defense system plays a vital role in maintaining life and health. Thus, constructing a highly sensitive sensor for detecting O2•− and enhancing antioxidant defense systems are of great significance for reducing the risk of diseases caused by oxidative stress. In this work, a MOF-derived carbon-based nanomaterial (AgNPs-MC) was synthesized through silver-based metal organic framework. The non-enzymatic O2•− electrochemical sensor fabricated by AgNPs-MC showed excellent catalytic ability, wide linear range, and an ultra-low detection limit (12.3 pM, S/N = 3). In addition, it could be successfully used to detect O2•− released by living cells. More importantly, the synergistic effect of superoxide dismutase (SOD) and tea polyphenols (TP) to scavenge O2•− in biological systems was first studied by electrochemical method, which provides a novel strategy for improving the antioxidant defense system of living cells. Constructed sensing platform and developed antioxidant strategy have potential value for their future application in the diagnosis and treatment of diseases related oxidative stress.