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Label-free upconversion nanoparticles-based fluorescent probes for sequential sensing of Cu 2+ , pyrophosphate and alkaline phosphatase activity
- Source :
- Biosensors and Bioelectronics. 95:21-26
- Publication Year :
- 2017
- Publisher :
- Elsevier BV, 2017.
-
Abstract
- An efficient near-infrared fluorescence probe has been developed for the sequential detection of Cu2+, pyrophosphate (P2O74-, PPi), and alkaline phosphatase (ALP), which is based on the "off-on-off" fluorescence switch of branched polyethyleneimine (PEI)-capped NaGdF4:Yb/Tm upconversion nanoparticles (UCNPs). The fluorescence is quenched via energy transfer from UCNPs to Cu2+ for the coordination of PEI with Cu2+. The strong affinity between Cu2+ and PPi leads to the formation of Cu2+-PPi complex and results in the detachment of Cu2+ from the surface of UCNPs, thus the fluorescence is triggered on. ALP-directed hydrolysis of PPi causes the disassembly of Cu2+-PPi complex and re-conjugation between Cu2+ with PEI, which leads to the switch-off fluorescence of UCNPs. The system allows sequential analysis of Cu2+, PPi, and ALP by modulating the switch of the fluorescence of UCNPs with detection limits of 57.8nM, 184nM, and 0.019U/mL for Cu2+, PPi, and ALP, respectively. By virtue of the NIR feature and excellent biocompatibility, the UCNPs-based probes are suitable for bioimaging. Taking Cu2+ visualization as a model, the nanoprobes have been successfully applied for intracellular imaging of Cu2+ in living cells.
- Subjects :
- Detection limit
Biocompatibility
Inorganic chemistry
Biomedical Engineering
Biophysics
02 engineering and technology
General Medicine
010402 general chemistry
021001 nanoscience & nanotechnology
01 natural sciences
Pyrophosphate
Fluorescence
0104 chemical sciences
Upconversion nanoparticles
chemistry.chemical_compound
Hydrolysis
chemistry
Electrochemistry
Alkaline phosphatase
0210 nano-technology
Intracellular
Biotechnology
Subjects
Details
- ISSN :
- 09565663
- Volume :
- 95
- Database :
- OpenAIRE
- Journal :
- Biosensors and Bioelectronics
- Accession number :
- edsair.doi...........2ea5b8c692ebb832958ec46ff8aebf86