A novel fluorescent assay for oxytetracycline hydrochloride based on fluorescence quenching of water‐soluble CdTe nanocrystals

Abstract

A novel assay for oxytetracycline hydrochloride (OTC) based on fluorescence quenching was developed from the interaction between functionalized cadmium telluride quantum dots (CdTe QDs) and OTC. Optimum conditions for the detection of OTC were found after investigating all factors. Under optimum conditions, luminescence of CdTe nanocrystals (λex = 365 nm, λem = 562 nm) was quenched by OTC in a concentration‐dependent manner best described by a modified Stern‐Volmer type equation. Good linearity was obtained with a regression coefficient of 0.9999 in the range of 1.34 ~ 13.4 x 10‐5 mol/L and a limit of detection of 3.08 x 10‐7 mol/L. In addition, the quenching mechanism was also established. The results imply that the close proximity of OTC‐CdTe was driven by electrostatic attraction and the resulting effective electron transfer from OTC to QDs could be responsible for fluorescence quenching of CdTe‐QDs. Copyright © 2012 John Wiley & Sons, Ltd.

Rapid microwave-assisted synthesis of molecularly imprinted polymers on carbon quantum dots for fluorescent sensing of tetracycline in milk

“…As shown in Fig. S7 (ESI †), the detection limit, calculated based on a 3σ/slope [39,40], was down to 5.48 nmol L -1 , which is lower or at least comparable to the sensors reported in recent years [18][19][20][21][22]. Meanwhile, the precision and reproducibility of the proposed sensor were also acceptable.…”

“…During the past decades, a series of fluorescent sensors have been designed to detect non-fluorescent Tc, such as proteins [17], Eu 3+ -based nanoparticles [18,19], metal-organic coordination polymers [20,21], CdTe quantum dots [22]. However, the reported sensors still lacked good anti-interference ability in complex samples, leading to false-positive test results.…”

Effects of representative quantum dots on microorganisms and phytoplankton: a comparative study

“…[21][22][23] Typically, CdTe-QDs modied with TGA were prepared from cadmium chloride and NaHTe solutions. Tellurium powder was mixed with sodium borohydride under N 2 for 30 min at 45 C. Then the mixture was injected into an N 2 -saturated Cd 2+ -TGA precursor solution (the molar ratio of Cd : Te : TGA was 1 : 0.5 : 2.4).…”

A rapid and sensitive assay for determination of doxycycline using thioglycolic acid-capped cadmium telluride quantum dots

“…Nowadays, quantum dots (QDs), a type of photoluminescent semiconductor nanomaterials, have been widely used as fluorescent labels and have provided significant improvements in quantitative determinations. Generally, quantum dots with capping ligands have been used in highly-sensitive bioanalytical assays such as detection and labeling of biomolecules [25][26][27][28]. Because of their outstanding optical properties, they have been widely used in the analysis of pharmaceutical such as paeonol [29], roxithromycin [30], ellagic acid [31], rifampicin [32], oxytetracycline [28] and sulfadiazine [33].…”

“…Generally, quantum dots with capping ligands have been used in highly-sensitive bioanalytical assays such as detection and labeling of biomolecules [25][26][27][28]. Because of their outstanding optical properties, they have been widely used in the analysis of pharmaceutical such as paeonol [29], roxithromycin [30], ellagic acid [31], rifampicin [32], oxytetracycline [28] and sulfadiazine [33]. These studies have revealed that the interactions between thioglycolic acid capped quantum dots (TGA/QDs) and some substances could moderate the photophysical properties of QDs.…”