A novel switchable fluorescent sensor for facile and highly sensitive detection of alkaline phosphatase activity in a water environment with gold/silver nanoclusters
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A novel fluorescent sensor based on bovine serum albumin stabilized gold/silver nanoclusters (BSA-Au/Ag NCs) was developed for sensitive and facile detection of alkaline phosphatase (ALP) activity. For this fluorescent sensor, ascorbic acid 2-phosphate (AAP) was decomposed into ascorbic acid (AA) and phosphate by catalysis with ALP. The initial red fluorescence of the BSA-Au/Ag NCs was effectively quenched by KMnO4 and then the fluorescence was recovered by addition of AA. The mechanism of interaction between BSA-Au/Ag NCs and KMnO4 and AA was studied with use of the fluorescence lifetime and UV-vis absorption spectra. The results indicated that the oxidation/reduction modulated by KMnO4/AA led to surface structure destruction/restoration of the BSA-Au/Ag NCs, resulting in fluorescence quenching/recovery. The proposed fluorescence-based method based on a dark background was used to detect ALP and had excellent sensitivity, with a detection limit of 0.00076 U/L. Moreover, the method was applied to the determination of added analytes, with satisfactory recoveries (97.0–105.0 %). In a simulated eutrophic water body, this method successfully detected ALP in actual water samples and could monitor the dynamic changes of ALP activity through visual observation. More importantly, the proposed fluorescent sensor not only has the advantages of simple operation and high sensitivity but has also been successfully used on filter paper to establish a rapid and visual test paper for ALP.
KeywordsAu/Ag nanoclusters stabilized with bovine serum albumin Alkaline phosphate activity Fluorescence quenching/recovery
This work was supported by the State Key Research Development Program of China (2017YFC1200103), the National Natural Science Foundation of China (NSFC-31200317, 31570414), the Senior Talent Scientific Research Initial Funding Project of Jiangsu University (11JDG1147, 14JDG051), the Priority Academic Program Development of Jiangsu Higher Education Institutions, and Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment.
Compliance with ethical standards
All authors contributed to the work, read the manuscript, and agreed to be listed as an author.
Conflict of interest
The authors declare that they have no competing interests.
- 4.Ardón M, Montanari S, Morse JL, Doyle MW, Bernhardt ES. Phosphorus export from a restored wetland ecosystem in response to natural and experimental hydrologic fluctuations. J Geophys Res Biogeosci. 2015;115:2532–4.Google Scholar
- 47.Zhang W, Ying G, Li Y, Zhang Q, Hu Z, Zhang Y, et al. Polyphosphoric acid-induced perylene probe self-assembly and label-free fluorescence turn-on detection of alkaline phosphatase. Anal Bioanal Chem. 2016;409:1–6.Google Scholar