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A ratiometric fluorescent assay for the detection and bioimaging of alkaline phosphatase based on near infrared Ag2S quantum dots and calcein
- Source :
- Biosensors and Bioelectronics. 137:148-153
- Publication Year :
- 2019
- Publisher :
- Elsevier BV, 2019.
-
Abstract
- Herein, a ratiometric fluorescent method was developed for alkaline phosphatase (ALP) detection based on near-infrared (NIR) Ag2S quantum dots (QDs) and calcein through the competitive approach. The system based on Ag2S QDs and calcein shows green (maximum emission at 512 nm from calcein) and near infrared (NIR) fluorescence (maximum 798 nm from Ag2S QDs) under the same excitation wavelength (468 nm). In the presence of Ce3+, the fluorescence intensity of calcein is decreased due to static quenching, while the fluorescence intensity of Ag2S QDs is enhanced through aggregation induced emission (AIE). The p-nitrophenyl phosphate is hydrolyzed by ALP, and the yield phosphate ions bind with Ce3+ with higher affinity than these of Ag2S QDs and calcein. Therefore, the green fluorescence from calcein is recovered while NIR fluorescence from Ag2S QDs is decreased. On the basis of these findings, a ratiometric fluorescence assay was developed for the measurement of ALP activity. The ratio of fluorescence intensity at 512 and 798 nm (F512/F798) was well associated with the ALP concentration ranging from 2 to 100 mU/mL with the detection limit of 1.28 mU/mL. The method was successfully applied for detecting ALP in human serum with an acceptable recovery and bioimaging intracellular ALP with good performance. In addition, the approach was also employed for the screening ALP inhibitor.
- Subjects :
- Detection limit
Quenching (fluorescence)
Chemistry
010401 analytical chemistry
Near-infrared spectroscopy
technology, industry, and agriculture
Biomedical Engineering
Biophysics
02 engineering and technology
General Medicine
equipment and supplies
021001 nanoscience & nanotechnology
Phosphate
01 natural sciences
Fluorescence
0104 chemical sciences
Calcein
chemistry.chemical_compound
Quantum dot
Electrochemistry
Alkaline phosphatase
0210 nano-technology
Biotechnology
Nuclear chemistry
Subjects
Details
- ISSN :
- 09565663
- Volume :
- 137
- Database :
- OpenAIRE
- Journal :
- Biosensors and Bioelectronics
- Accession number :
- edsair.doi...........8f63b6d6a3aed1191ec69afe952aae46