CdTe Quantum Dots Modified with Cysteamine: A New Efficient Nanosensor for the Determination of Folic Acid
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 micro...
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doaj-22aec525731f424f90c884f3d96acda02020-11-25T02:16:45ZengMDPI AGSensors1424-82202019-10-011920454810.3390/s19204548s19204548CdTe Quantum Dots Modified with Cysteamine: A New Efficient Nanosensor for the Determination of Folic AcidDoris E. Ramírez-Herrera0Ana Patricia Reyes-Cruzaley1Giselle Dominguez2Francisco Paraguay-Delgado3Antonio Tirado-Guízar4Georgina Pina-Luis5Tecnológico Nacional de México/Instituto Tecnológico de Tijuana, Centro de Graduados e Investigación, A.P. 1166, Tijuana 22500, MexicoTecnológico Nacional de México/Instituto Tecnológico de Tijuana, Centro de Graduados e Investigación, A.P. 1166, Tijuana 22500, MexicoMiami Dade College, North Campus, 11380 NW 27th Ave, Miami, FL 33167, USACentro de Investigación en Materiales Avanzados S. C., Departamento de Física de Materiales, Av. Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua CP 31136, MexicoTecnológico Nacional de México/Instituto Tecnológico de Tijuana, Centro de Graduados e Investigación, A.P. 1166, Tijuana 22500, MexicoTecnológico Nacional de México/Instituto Tecnológico de Tijuana, Centro de Graduados e Investigación, A.P. 1166, Tijuana 22500, MexicoIn 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 μM (R<sup>2</sup> = 0.9944), with a detection limit of 0.048 μM. 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.https://www.mdpi.com/1424-8220/19/20/4548folic acid nanosensorpositive quantum dotsfluorescence quenchingelectron transfer |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Doris E. Ramírez-Herrera Ana Patricia Reyes-Cruzaley Giselle Dominguez Francisco Paraguay-Delgado Antonio Tirado-Guízar Georgina Pina-Luis |
spellingShingle |
Doris E. Ramírez-Herrera Ana Patricia Reyes-Cruzaley Giselle Dominguez Francisco Paraguay-Delgado Antonio Tirado-Guízar Georgina Pina-Luis CdTe Quantum Dots Modified with Cysteamine: A New Efficient Nanosensor for the Determination of Folic Acid Sensors folic acid nanosensor positive quantum dots fluorescence quenching electron transfer |
author_facet |
Doris E. Ramírez-Herrera Ana Patricia Reyes-Cruzaley Giselle Dominguez Francisco Paraguay-Delgado Antonio Tirado-Guízar Georgina Pina-Luis |
author_sort |
Doris E. Ramírez-Herrera |
title |
CdTe Quantum Dots Modified with Cysteamine: A New Efficient Nanosensor for the Determination of Folic Acid |
title_short |
CdTe Quantum Dots Modified with Cysteamine: A New Efficient Nanosensor for the Determination of Folic Acid |
title_full |
CdTe Quantum Dots Modified with Cysteamine: A New Efficient Nanosensor for the Determination of Folic Acid |
title_fullStr |
CdTe Quantum Dots Modified with Cysteamine: A New Efficient Nanosensor for the Determination of Folic Acid |
title_full_unstemmed |
CdTe Quantum Dots Modified with Cysteamine: A New Efficient Nanosensor for the Determination of Folic Acid |
title_sort |
cdte quantum dots modified with cysteamine: a new efficient nanosensor for the determination of folic acid |
publisher |
MDPI AG |
series |
Sensors |
issn |
1424-8220 |
publishDate |
2019-10-01 |
description |
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 μM (R<sup>2</sup> = 0.9944), with a detection limit of 0.048 μM. 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. |
topic |
folic acid nanosensor positive quantum dots fluorescence quenching electron transfer |
url |
https://www.mdpi.com/1424-8220/19/20/4548 |
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