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CdTe Quantum Dots Modified with Cysteamine: A New Efficient Nanosensor for the Determination of Folic Acid
- Source :
- Sensors, Volume 19, Issue 20, Sensors (Basel, Switzerland), Sensors, Vol 19, Iss 20, p 4548 (2019)
- Publication Year :
- 2019
- Publisher :
- Multidisciplinary Digital Publishing Institute, 2019.
-
Abstract
- In this paper, we report the synthesis, characterization, and application of a new fluorescent nanosensor based on water-soluble CdTe quantum dots (QDs) coated with cysteamine (CA) for the determination of folic acid (FA). CdTe/CA QDs were characterized by high-resolution transmission electron microscopy, the zeta potential, and Fourier-transform infrared (FT-IR), UV-visible, and fluorescence spectroscopy. CdTe QDs coated with mercaptopropionic acid (MPA) and glutathione (GSH) were prepared for comparison purposes. The effect of FA on the photoluminescence intensity of the three thiol-capped QDs at pH 8 was studied. Only CdTe/CA QDs showed a notable fluorescence quenching in the presence of FA. Then, a nanosensor based on the fluorescence quenching of the CdTe QDs at pH 8 was explored. Under optimum conditions, the calibration curve showed a linear fluorescence quenching response in a concentration range of FA from 0.16 to 16.4 &mu<br />M (R2 = 0.9944), with a detection limit of 0.048 &mu<br />M. A probable mechanism of fluorescence quenching was proposed. The nanosensor showed good selectivity over other possible interferences. This method has been applied for FA quantification in orange beverage samples with excellent results (recoveries from 98.3 to 103.9%). The good selectivity, sensitivity, low cost, and rapidity make CdTe /CA QDs a suitable nanosensor for FA determination.
- Subjects :
- positive quantum dots
Photoluminescence
fluorescence quenching
02 engineering and technology
010402 general chemistry
lcsh:Chemical technology
01 natural sciences
Biochemistry
Fluorescence spectroscopy
Article
Analytical Chemistry
Nanosensor
Zeta potential
lcsh:TP1-1185
Electrical and Electronic Engineering
Instrumentation
folic acid nanosensor
Detection limit
Chemistry
021001 nanoscience & nanotechnology
electron transfer
Fluorescence
Atomic and Molecular Physics, and Optics
0104 chemical sciences
Quantum dot
0210 nano-technology
Selectivity
Nuclear chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 14248220
- Database :
- OpenAIRE
- Journal :
- Sensors
- Accession number :
- edsair.doi.dedup.....f6b7da09b9c3cf0ab668531fb63e8360
- Full Text :
- https://doi.org/10.3390/s19204548