AbstractThe authors describe a colorimetric method for the determination of the activity of acetylcholinesterase (AChE). Manganese dioxide (MnO2) nanosheets directly reacts with 3,3′,5,5′–tetramethylbenzidine (TMB) in the absence of hydrogen peroxide (H2O2). This leads to the formation of a blue product (oxTMB) with an absorption peak at 652 nm. If AChE hydrolyzes its substrate acetylthiocholine chloride, thiocholine is formed which blocks the oxidative power of the MnO2 nanosheets. Hence, oxTMB will not be formed. The decreased absorbance is directly related to the AChE activity in the 0.01–1.0 mU·mL−1 range. The detection limit is 0.01 mU·mL−1 and the relative standard deviation is 1.2% (for n = 11 at 0.5 mU·mL−1). The method was also applied to screen for inhibitors of AChE. Graphical abstractBased on the oxidizing properties of manganese dioxide nanosheets (MnO2 nanosheets), we report a colorimetric method for determining acetylcholinesterase activity with the chromogenic substrate 3,3′,5,5′-tetramethylbenzidine (TMB).

中文翻译：

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基于硫代胆碱诱导的 MnO2 纳米片对 3,3',5,5'-四甲基联苯胺氧化能力的抑制作用的乙酰胆碱酯酶活性比色分析和抑制剂筛选

摘要作者描述了一种测定乙酰胆碱酯酶 (AChE) 活性的比色法。二氧化锰 (MnO2) 纳米片在没有过氧化氢 (H2O2) 的情况下直接与 3,3',5,5'-四甲基联苯胺 (TMB) 反应。这导致形成蓝色产物 (oxTMB)，在 652 nm 处具有吸收峰。如果 AChE 水解其底物乙酰硫代胆碱氯化物，则会形成硫代胆碱，从而阻止 MnO2 纳米片的氧化能力。因此，不会形成 oxTMB。降低的吸光度与 0.01–1.0 mU·mL-1 范围内的 AChE 活性直接相关。检测限为 0.01 mU·mL-1，相对标准偏差为 1.2%（n = 11 在 0.5 mU·mL-1 时）。该方法还用于筛选 AChE 抑制剂。