The peroxidase-mimicking function of acetate and its application in single-enzyme-based glucose test paper

Acetate ion was widely used in pH buffer to control pH environment. Here we firstly found that acetate ion had mimic peroxidase activity. Acetate ions are capable of catalyzing the decomposition of hydrogen peroxide and play a similar role to that of horseradish peroxidase (HRP). Acetate catalyzes the oxidation of tetramethylbenzidine (TMB) by H₂O₂, which is the product of the reaction of glucose and glucose oxidase. A colorimetric sensor for H₂O₂ and glucose was developed using acetate ions. The linear regression equation for H₂O₂ was A = 0.0029 C + 0.0530 (C (μmolL^-1), R = 0.9978), and the detection limit was 3.0 μmolL^-1, whereas that for glucose was A = 0.0021 C + 0.0709 (C (μmol L^-1), R = 0.9977), and the detection limit was 4.0 μmol L^-1. Moreover, the proposed method was successfully applied for the detection of H₂O₂ in human urine and glucose in human serum; thus, the proposed method could be used for the diagnosis of illness or disease. A single-enzyme-based glucose test paper was firstly prepared and tested for semi-quantitative analysis of glucose.