Mercaptopropionic acid–capped CdTe quantum dots as fluorescence probe for the determination of salicylic acid in pharmaceutical products

Abstract

Mercaptopropionic acid (MPA)-capped cadmium telluride (CdTe) quantum dot (QDs) fluorescent probes were synthesized in aqueous solution and used for the determination of salicylic acid. The interaction between the MPA-capped CdTe QDs and salicylic acid was studied using fluorescence spectroscopy and some parameters that could modify the fluorescence were investigated to optimize the measurements. Under optimum conditions, the quenched fluorescence intensity of MPA-capped CdTe QDs was linearly proportional to the concentration of salicylic acid in the range of 0.5-40 µg mL(-1) with a coefficient of determination of 0.998, and the limit of detection was 0.15 µg mL(-1). The method was successfully applied to the determination of salicylic acid in pharmaceutical products, and satisfactory results were obtained that were in agreement with both the high pressure liquid chromatography (HPLC) method and the claimed values. The recovery of the method was in the range 99 ± 3% to 105 ± 9%. The proposed method is simple, rapid, cost effective, highly sensitivity and eminently suitable for the quality control of pharmaceutical preparation. The possible mechanisms for the observed quenching reaction was also discussed.

A simple and sensitive label‐free fluorescence sensing of heparin based on Cdte quantum dots

“…Heparin is not a single well known molecule, but it is rather typically considered as a whole family of polysaccharides with an average molecular weight of 12 000 to 15 000 and an average charge of 75. Under physiological conditions, heparin is a highly negatively charged glycosaminoglycan due to totally ionized sulfate (–OSO 3 , –NHSO 3 ) and carboxylate (–COO) groups . The structure of heparin is shown in Fig.…”

A nanocomposite optosensor containing carboxylic functionalized multiwall carbon nanotubes and quantum dots incorporated into a molecularly imprinted polymer for highly selective and sensitive detection of ciprofloxacin

“…CdTe QDs showed a narrow and symmetric fluorescence spectrum with the maximum emission wavelength being 540nm. The calculated particle size of the TGA-capped CdTe QDs was2.10nm using the method described in previous work [12]. (Fig.…”

“…QDs have been used for the determination of various target analytes at trace levels typical analytes include salicylic acid [12], glucose [13], H2O2 [14], 6-mercaptopurine [15], ochratoxin A [16], kaempferol [17] and copper (II) ion [18]. In addition, QDs have many unique optical properties such as tunable size-dependent photoluminescence, good photostability and narrow symmetric emissions [19,20].…”

Design, Synthesis, and Enzymatic Evaluation of Novel ZnO Quantum Dot-Based Assay for Detection of Proteinase 3 Activity

“…1,4,5 Similar to organic fluorophores, semiconductor nanocrystals can act as energy donors with organic dyes as energy acceptors in fluorescence resonance energy transfer (FRET) assays. 6 Various FRET-based QD biosensors have been reported thus far, including the detection of glucose, 7 melamine, 8 kaempferol, 9 nucleic acids, 10,11 aflatoxin, 12 trypsin, 9,13,14 dopamine, 15 avidin, 16 salicylic acid, 17 DNA, 18 protease, 4,19,20 glutathione, 21 caspase 3, 22 and protein kinase. 23 The most commonly used QDs for biosensors are CdTe, 8,9,12,17,21 CdS, 11 graphene QDs, 10,[13][14][15]23 ZnS-CdSe, 16 CdSe/CdS core/shell, 18 CdSe/ZnS core/shell, 7,19,22 and CdSeS/ZnS core/shell.…”

“…The recent progress in surface functionalization with organic ligands as well as the controlled synthesis of high-quality QDs enables their use in cell targeting, bioimaging, drug delivery, and disease diagnosis. − QDs possess unique properties, such as broad absorption spectra, narrow and symmetric size-dependent emission, high quantum yield, and stability against photobleaching, which make them advantageous over traditional organic dyes and fluorescent proteins for biosensing applications. ,, Similar to organic fluorophores, semiconductor nanocrystals can act as energy donors with organic dyes as energy acceptors in fluorescence resonance energy transfer (FRET) assays . Various FRET-based QD biosensors have been reported thus far, including the detection of glucose, melamine, kaempferol, nucleic acids, , aflatoxin, trypsin, ,, dopamine, avidin, salicylic acid, DNA, protease, ,, glutathione, caspase 3, and protein kinase . The most commonly used QDs for biosensors are CdTe, ,,,, CdS, graphene QDs, ,− , ZnS-CdSe, CdSe/CdS core/shell, CdSe/ZnS core/shell, ,, and CdSeS/ZnS core/shell .…”