scholarly journals CdTe Quantum Dots Modified with Cysteamine: A New Efficient Nanosensor for the Determination of Folic Acid

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4548 ◽  
Author(s):  
Doris E. Ramírez-Herrera ◽  
Ana Patricia Reyes-Cruzaley ◽  
Giselle Dominguez ◽  
Francisco Paraguay-Delgado ◽  
Antonio Tirado-Guízar ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Folic Acid ◽  
Fluorescence Quenching ◽  
Low Cost ◽  
Water Soluble ◽  
Cdte Quantum Dots ◽  
Photoluminescence Intensity ◽  
Beverage Samples ◽  
Cdte Qds

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 (R2 = 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.

Rapid determination of melamine in milk using water-soluble CdTe quantum dots as fluorescence probes

2011 ◽  
pp. 1-12 ◽  
Author(s):  
Minwei Zhang† ◽  
Hong Ping† ◽  
Xianyi Cao ◽  
Hongkun Li ◽  
Fengrui Guan ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Rapid Determination ◽  
Water Soluble ◽  
Cdte Quantum Dots ◽  
Fluorescence Probes

Fluorescence suppression of MPA stabilized CdTe QDs for direct determination of propranolol

2017 ◽  
Vol 9 (6) ◽  
pp. 929-936 ◽  
Author(s):  
Fan Zhang ◽  
Miaomiao Chen ◽  
Haiqing Zhang ◽  
Huayu Xiong ◽  
Wei Wen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Fluorescent Sensor ◽  
Direct Determination ◽  
Cdte Quantum Dots ◽  
Mercaptopropionic Acid ◽  
Cdte Qds

A sensitive, convenient and rapid fluorescent sensor for effectively and directly detecting propranolol was proposed based on the fluorescence suppression of 3-mercaptopropionic acid stabilized CdTe quantum dots.

Determination of iron in biodiesel based on fluorescence quenching of CdTe quantum dots

Fuel ◽  
2014 ◽  
Vol 117 ◽  
pp. 520-527 ◽  
Author(s):  
S. Sofia M. Rodrigues ◽  
Adriana S. Lima ◽  
Leonardo S.G. Teixeira ◽  
Maria das Graças A. Korn ◽  
João L.M. Santos
Keyword(s):  
Quantum Dots ◽  
Fluorescence Quenching ◽  
Cdte Quantum Dots

A novel and sensitive turn-on fluorescent biosensor for the determination of thioctic acid based on Cu2+-modulated N-acetyl-l-cysteine capped CdTe quantum dots

RSC Advances ◽  
2015 ◽  
Vol 5 (55) ◽  
pp. 44173-44182 ◽  
Author(s):  
Xuanping Tan ◽  
Qin Li ◽  
Xiaoning Zhang ◽  
Yizhong Shen ◽  
Jidong Yang
Keyword(s):  
Quantum Dots ◽  
Aqueous Media ◽  
Fluorescence Sensor ◽  
Cdte Quantum Dots ◽  
Thioctic Acid ◽  
Fluorescent Biosensor ◽  
Turn On ◽  
Cdte Qds

A new fluorescence sensor for the determination of thioctic acid (TA) in aqueous media based on the recovered fluorescence of N-acetyl-l-cysteine capped CdTe quantum dots [NALC-CdTe QDs]–Cu2+ system was proposed.

Application of CdTe Quantum Dots to Development Fingerprints on Adhesive Surfaces

2011 ◽  
Vol 694 ◽  
pp. 874-880 ◽  
Author(s):  
Rui Qin Yang ◽  
Yong Gang Wang ◽  
Bin Bin Xia ◽  
Yan Ji Wang ◽  
Jian Jun Liu
Keyword(s):  
Quantum Dots ◽  
Fluorescence Spectroscopy ◽  
Fluorescence Intensity ◽  
Development Time ◽  
Ph Value ◽  
Development Rate ◽  
Water Soluble ◽  
Cdte Quantum Dots ◽  
Cdte Qds ◽  
Effective Development

Water-soluble fluorescent CdTe quantum dots were synthesized using TGA (Thiolglycolic acid) as the stabilizer and characterized by fluorescence spectroscopy. This fluorescent material was applied to development fingerprints deposited on the sticky side of adhesives. The development conditions such as development time, temperature and pH value of QDs solution were investigated. The comparison experimental with traditional methods and development rate were also studied. The results show that this material exhibited strong visible fluorescence under excitation at 365 nm. CdTe QDs can detect fingerprints on different adhesive surfaces. In addition, the development rate of fingerprints on the adhesive side of cellulose tape was discussed and the effective development rate for 30-days-aged fingerprints can reach to 72%. Furthermore, the developed fingerprints have higher and stable fluorescence intensity, weaker background interference and better contrast between fingerprints and the substrate. CdTe QDs is a promising reagent for fingerprints development on adhesive surfaces.

Determination of particle size distribution of water-soluble CdTe quantum dots by optical spectroscopy

RSC Advances ◽  
2014 ◽  
Vol 4 (68) ◽  
pp. 36024-36030 ◽  
Author(s):  
J. C. L. Sousa ◽  
M. G. Vivas ◽  
J. L. Ferrari ◽  
C. R. Mendonca ◽  
M. A. Schiavon
Keyword(s):  
Quantum Dots ◽  
Particle Size ◽  
Optical Properties ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Water Soluble ◽  
Cdte Quantum Dots ◽  
One Pot ◽  
The One

In the present study, we report the synthesis of glutathione (GSH) capped CdTe quantum dots (QDs) using the one-pot approach as well as their optical properties.

l-Cysteine-capped CdTe quantum dots as a fluorescent probe for sequential detection of lysozyme and trypsin

2017 ◽  
Vol 41 (10) ◽  
pp. 4138-4144 ◽  
Author(s):  
Fanping Shi ◽  
Siyu Liu ◽  
Xingguang Su
Keyword(s):  
Quantum Dots ◽  
Fluorescent Probe ◽  
Fluorescence Assay ◽  
Cdte Quantum Dots ◽  
Sequential Detection ◽  
Sequential Determination ◽  
Cdte Qds

A fluorescence assay for the sequential determination of lysozyme and trypsin was established based on l-cysteine capped CdTe quantum dots. Lysozyme with positive charges can interact with l-cysteine capped CdTe quantum dots. Lysozyme can be hydrolyzed into small fragments in the presence of trypsin, and the interaction between l-cysteine-capped CdTe QDs and lysozyme would be inhibited, which could be used for trypsin quantification.

scholarly journals Determination of Folic Acid Using Biosensors—A Short Review of Recent Progress

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3360
Author(s):  
Alessio Di Tinno ◽  
Rocco Cancelliere ◽  
Laura Micheli
Keyword(s):  
Folic Acid ◽  
Biological Fluid ◽  
Low Cost ◽  
Analytical Techniques ◽  
Short Review ◽  
Electrochemical Determination ◽  
Water Soluble ◽  
Methylation Of Dna ◽  
Vitamin B9

Folic acid (FA) is the synthetic surrogate of the essential B vitamin folate, alternatively named folacin, pteroylglutamic acid or vitamin B9. FA is an electroactive compound that helps our body to create and keep our cells healthy: it acts as the main character in a variety of synthetic biological reactions such as the synthesis of purines, pyrimidine (thus being indirectly implied in DNA synthesis), fixing and methylation of DNA. Therefore, physiological folate deficiency may be responsible for severe degenerative conditions, including neural tube defects in developing embryos and megaloblastic anaemia at any age. Moreover, being a water-soluble molecule, it is constantly lost and has to be reintegrated daily; for this reason, FA supplements and food fortification are, nowadays, extremely diffused and well-established practices. Consequently, accurate, reliable and precise analytical techniques are needed to exactly determine FA concentration in various media. Thus, the aim of this review is to report on research papers of the past 5 years (2016–2020) dealing with rapid and low-cost electrochemical determination of FA in food or biological fluid samples.

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