Fenton and Fenton-like catalysts for electrochemical immunoassay: A mini review

With the rapid development of electrochemical immunoassay, various catalysts have been applied for initiating catalytic reaction to improve the sensitivity of electrochemical immunosensor. Sensitivity, the change in electrochemical signal caused by antigen per unit concentration, is a crucial indictor to evaluate the performance of electrochemical immunosensor for detecting tumor markers. As a traditional inorganic reaction, Fenton and Fenton-like reaction has been widely used in amplifying sensitivity, owing to their fast reaction, mild reaction conditions, low cost and environmental friendliness. By virtue of these advantages, increasingly Fenton and Fenton-like catalysts with high catalytic efficiency have been exploited in conceiving immunosensor. Herein, recent progresses in Fenton and Fenton-like catalysts including Fe3O4, iron-based metal organic frameworks, iron-based hydrogel, hemin, ferrous reagent and iron-free catalysts like metallic peroxide and noble metal particles are summarized. The remaining challenges and prospects for future directions for the rational application of Fenton and Fenton-like catalysts are also discussed.