College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, People's Republic of China.
Analyst. 2020 Jun 7;145(11):3871-3877. doi: 10.1039/d0an00052c. Epub 2020 Apr 16.
In this work, a simple and sensitive method based on the inner filter effect (IFE) of p-nitrophenol (PNP) on the fluorescence of gold nanoclusters (AuNCs) has been developed for detecting alkaline phosphatase (ALP) activity. Bright orange fluorescent AuNCs were synthesized by one-pot synthesis and used directly as IFE fluorophores. p-Nitrophenyl phosphate (PNPP) is hydrolyzed by ALP to PNP, which quenches the fluorescence of AuNCs by the IFE. In the presence of ALP, PNPP was converted to PNP, and the absorption band shifted from 310 nm to 405 nm, which resulted in a certain degree of overlap between the absorption of PNP and the excitation of AuNCs. Due to the competitive absorption between AuNCs and PNP, the excitation of AuNCs was clearly diminished, leading to the quenching of the fluorescence of AuNCs. The IFE detection method exhibited a good linear relationship between 0.01 and 7.0 U L (R = 0.9990) with the lowest detection limit of 0.003 U L (the signal-to-noise ratio is 3). The proposed detection method was successfully applied for detecting ALP in serum samples and studying ALP inhibitors.
在这项工作中，基于对金纳米簇（AuNCs）荧光的对硝基苯酚（PNP）的内滤效应（IFE），开发了一种简单灵敏的方法，用于检测碱性磷酸酶（ALP）活性。通过一锅合成法合成了明亮的橙色荧光 AuNCs，并直接用作 IFE 荧光团。碱性磷酸酶（ALP）将 p-硝基苯磷酸酯（PNPP）水解为 PNP，通过 IFE 猝灭 AuNCs 的荧光。在存在 ALP 的情况下，PNPP 被转化为 PNP，吸收带从 310nm 移至 405nm，导致 PNP 的吸收与 AuNCs 的激发之间存在一定程度的重叠。由于 AuNCs 和 PNP 之间的竞争吸收，AuNCs 的激发明显减弱，导致 AuNCs 的荧光猝灭。IFE 检测方法在 0.01 到 7.0 U L 之间表现出良好的线性关系（R = 0.9990），最低检测限为 0.003 U L（信噪比为 3）。该检测方法成功应用于血清样品中 ALP 的检测和 ALP 抑制剂的研究。
