School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu 211166, China.
School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, Jiangsu 210023, China.
ACS Biomater Sci Eng. 2020 May 11;6(5):3132-3138. doi: 10.1021/acsbiomaterials.0c00217. Epub 2020 Apr 30.
In this research, we attempted to develop a sensitive colorimetric sensing strategy for the detection of acid phosphatase (ACP) based on MnO nanosheets and explored its applications in screening and evaluating inhibitors of ACP. The MnO nanosheets exhibit intrinsic biomimetic oxidase activity, which can catalyze the oxidation of the colorless 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonate) diammonium salt (ABTS) into green oxidized ABTS (oxABTS). Upon the introduction of ACP, l-ascorbic acid-2-phosphate can be dephosphorylated to ascorbic acid, which arouses the disintegration of MnO nanosheets into Mn ions. This disintegration weakens the enzyme mimicking activity of the MnO nanosheets, leading to the impediment of the oxidation of ABTS. Conversely, in the absence of ACP, the ABTS is rapidly oxidized by MnO, leading to a significant colorimetric signal change. The absorbance difference at 420 nm displayed a linear relationship with the concentration of ACP ranging from 0.075 to 0.45 mU·mL, generating a detection limit of 0.046 mU·mL. In the inhibition assays, this sensing platform provided simple detection for parathion-methyl (PM), a representative inhibitor of ACP. The facile evaluation of the inhibitory effect of PM, including its IC50 toward ACP, was also realized.
在这项研究中，我们试图开发一种基于 MnO 纳米片的灵敏比色传感策略来检测酸性磷酸酶（ACP），并探索其在 ACP 抑制剂筛选和评估中的应用。MnO 纳米片具有内在的仿生氧化酶活性，可催化无色 2,2'-联氮双（3-乙基苯并噻唑啉-6-磺酸）二铵盐（ABTS）氧化为绿色氧化 ABTS（oxABTS）。在引入 ACP 后，l-抗坏血酸-2-磷酸可以被去磷酸化为抗坏血酸，这会引起 MnO 纳米片分解为 Mn 离子。这种分解削弱了 MnO 纳米片的酶模拟活性，阻碍了 ABTS 的氧化。相反，在没有 ACP 的情况下，ABTS 被 MnO 迅速氧化，导致明显的比色信号变化。在 420nm 处的吸光度差异与 ACP 的浓度呈线性关系，范围从 0.075 到 0.45 mU·mL，检测限为 0.046 mU·mL。在抑制试验中，该传感平台为 ACP 的代表性抑制剂对硫磷（PM）提供了简单的检测。还实现了对 PM 抑制效果的简便评估，包括其对 ACP 的 IC50。
