In this work, we report a fluorescent probe (TPEQN-P) for detecting alkaline phosphatase (ALP) with high sensitivity and monitoring its activity based on the specific aggregation-induced emission (AIE) effect. TPEQN-P can be constructed by conjugating the phosphate moiety into an AIE molecule (TPE-QI) through a reactive p-hydroxybenzyl group, which exhibits very weak emission in aqueous media due to its good water solubility. In the presence of ALP, TPEQN-P undergoes dephosphorylation and releases the hydrolysis product TPE-QI, which is intensely fluorescent because of its poor water solubility. The detection limit for ALP using TPEQN-P can be as low as 0.0077 U L⁻¹ with a linear range of 0–30 mU mL⁻¹ in solution. TPEQN-P also shows excellent applicability in serum samples, demonstrating potential applications in clinical diagnosis and biomedical research. TPEQN-P also can be applied for the determination of ALP activity and in ALP inhibitor screening.

中文翻译：

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一种敏感的碱性磷酸酶荧光探针和基于聚集诱导发射效应的活性测定†

在这项工作中，我们报告了一种荧光探针 (TPEQN-P)，用于高灵敏度检测碱性磷酸酶 (ALP) 并基于特定的聚集诱导发射 (AIE) 效应监测其活性。TPEQN-P 可以通过将磷酸盐部分通过反应性对羟基苄基结合成 AIE 分子 (TPE-QI) 来构建，由于其良好的水溶性，其在水性介质中表现出非常弱的发射。在 ALP 存在下，TPEQN-P 发生去磷酸化并释放出水解产物 TPE-QI，由于其水溶性差，因此具有强烈的荧光。使用 TPEQN-P 对 ALP 的检测限可低至 0.0077 UL ^-1，线性范围为 0–30 mU mL ^-1在溶液中。TPEQN-P在血清样本中也显示出极好的适用性，在临床诊断和生物医学研究中显示出潜在的应用。TPEQN-P 还可用于测定 ALP 活性和筛选 ALP 抑制剂。