{"title":"Fluorogenic response of thiamine triggered by Cu2+ for sensitive and economical determination of alkaline phosphatase","authors":"Hongding Zhang, Changlu Ke, Zhenhua Xing, Mengqi Zhao, Xin Xiang, Hai-Bo Wang","doi":"10.1007/s00216-025-06040-6","DOIUrl":null,"url":null,"abstract":"<div><p>Although fluorescent probes have been used extensively for alkaline phosphatase (ALP) sensing, most involve a tedious, prolonged, or high-cost synthesis procedure. Thus, it is still necessary to develop convenient and economical fluorescent probes for sensitive determination of ALP. Herein, a facile fluorescent strategy was designed for ALP detection utilizing the fluorogenic response of thiamine (TH) triggered by Cu<sup>2+</sup> (Cu<sup>2+</sup>-TH system). It was found that Cu<sup>2+</sup> facilitated the oxidation of non-fluorescent TH to fluorescent thiochrome (TC) in an alkaline environment, while pyrophosphoric acid (PPi) interacted with Cu<sup>2+</sup> to form PPi-Cu<sup>2+</sup> chelates, preventing the oxidation of TH to fluorescent TC. Consequently, a faint fluorescence output was detected in the system. After adding ALP into this system, PPi was catalyzed to phosphate (Pi), which combined weakly with Cu<sup>2+</sup>. A large amount of TH was oxidized into fluorescent TC by free Cu<sup>2+</sup>, leading to high fluorescence. Therefore, an ALP sensing platform was constructed by utilizing the fluorogenic reaction of the Cu<sup>2+</sup>-TH system as the signal reporter. The assay exhibited favorable analytical performance for ALP measurement. A linear correlation was obtained between the ALP concentration (0.01–1 mU/mL) and the fluorescence intensity of the Cu<sup>2+</sup>-TH system, with a limit of detection as low as 0.0038 mU/mL. Additionally, the assay was further employed for analyzing ALP content in complex biological samples. This work thus advances the science of in situ fluorogenic reaction in the field of biosensing.</p><h3>Graphical Abstract</h3>\n<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":462,"journal":{"name":"Analytical and Bioanalytical Chemistry","volume":"417 23","pages":"5211 - 5220"},"PeriodicalIF":3.8000,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Analytical and Bioanalytical Chemistry","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1007/s00216-025-06040-6","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIOCHEMICAL RESEARCH METHODS","Score":null,"Total":0}
引用次数: 0
Abstract
Although fluorescent probes have been used extensively for alkaline phosphatase (ALP) sensing, most involve a tedious, prolonged, or high-cost synthesis procedure. Thus, it is still necessary to develop convenient and economical fluorescent probes for sensitive determination of ALP. Herein, a facile fluorescent strategy was designed for ALP detection utilizing the fluorogenic response of thiamine (TH) triggered by Cu2+ (Cu2+-TH system). It was found that Cu2+ facilitated the oxidation of non-fluorescent TH to fluorescent thiochrome (TC) in an alkaline environment, while pyrophosphoric acid (PPi) interacted with Cu2+ to form PPi-Cu2+ chelates, preventing the oxidation of TH to fluorescent TC. Consequently, a faint fluorescence output was detected in the system. After adding ALP into this system, PPi was catalyzed to phosphate (Pi), which combined weakly with Cu2+. A large amount of TH was oxidized into fluorescent TC by free Cu2+, leading to high fluorescence. Therefore, an ALP sensing platform was constructed by utilizing the fluorogenic reaction of the Cu2+-TH system as the signal reporter. The assay exhibited favorable analytical performance for ALP measurement. A linear correlation was obtained between the ALP concentration (0.01–1 mU/mL) and the fluorescence intensity of the Cu2+-TH system, with a limit of detection as low as 0.0038 mU/mL. Additionally, the assay was further employed for analyzing ALP content in complex biological samples. This work thus advances the science of in situ fluorogenic reaction in the field of biosensing.
期刊介绍:
Analytical and Bioanalytical Chemistry’s mission is the rapid publication of excellent and high-impact research articles on fundamental and applied topics of analytical and bioanalytical measurement science. Its scope is broad, and ranges from novel measurement platforms and their characterization to multidisciplinary approaches that effectively address important scientific problems. The Editors encourage submissions presenting innovative analytical research in concept, instrumentation, methods, and/or applications, including: mass spectrometry, spectroscopy, and electroanalysis; advanced separations; analytical strategies in “-omics” and imaging, bioanalysis, and sampling; miniaturized devices, medical diagnostics, sensors; analytical characterization of nano- and biomaterials; chemometrics and advanced data analysis.