Sensitive Detection Of Tetracycline Research Articles

Carbon quantum dots derived from marine Eucheuma denticulatum for the efficient and sensitive detection of tetracycline

Carbon quantum dots derived from marine Eucheuma denticulatum for the efficient and sensitive detection of tetracycline

Construction of a stable fluorescent sensor based on CsPbBr3/CdS core/shell quantum dots for selective and sensitive detection of tetracycline in ethanol.

The weakly bound organic ligand shells around perovskite quantum dots (QDs) are easily decomposed and cannot provide sufficient stability in polar solvents, which greatly obstructs their applications in sensing. Herein, a fluorescent sensor based on CsPbBr3/CdS core/shell QDs was developed for the detection of tetracycline (TC) in the polar solvent-ethanol. Pristine CsPbBr3 QDs were treated with cadmium diethyldithiocarbamate (Cd(DDTC)2) to form a shell on the surface at 110 °C, while extra oleylammonium bromide (OAmBr) was added to inhibit the phase transformation of CsPbBr3 into a Cs4PbBr6 impurity phase during high-temperature processing. And finally CsPbBr3/CdS core/shell QDs were successfully synthesized. The capping with the CdS inorganic shell remediated surface defects and improved the stability in ethanol without affecting the emission properties of the parent CsPbBr3 QDs. The results showed that the fluorescent sensor detected TC in the range of 0.05-25 μM with a low detection limit of 22.6 nM, whereas it had high selectivity and anti-interference ability for TC. And the fluorescence quenching mechanism of the sensor was mainly photoinduced electron transfer between TC and CsPbBr3/CdS QDs. Our research provides a unique way to improve the stability of perovskite QDs in polar solvents and applications in fluorescence detection.

Carbon dots-based fluorescent molecularly imprinted photonic crystal hydrogel strip: Portable and efficient strategy for selective detection of tetracycline in foods of animal origin

Rapid, portable, and sensitive detection of tetracycline (TC) is crucial for the environment and human health. In this study, we developed carbon dots (CDs)-based fluorescent molecularly imprinted photonic crystal hydrogel (FMIPH) strips for TC detection in animal-derived foods. CDs emit fluorescent signals, and molecularly imprinted polymers provide specific recognition sites for TC. Inverse opal photonic crystals afford stable 3D macroporous mass transfer channels that considerably reduce binding time between TC and the strips. The portable FMIPH strip exhibited a linear fluorescence response to TC in the concentration range of 0.1–50 μg mL−1, with a detection limit of 0.067 μg mL−1. Good recoveries of TC (93.86–112.59%) were observed in TC-spiked commercially available pork, eggs, and milk. A combination of FMIPH strips with a portable fluorescent reading device could achieve sensitive, on-site, and real-time detection of TC in animal-derived foods.

A novel micron europium cluster coordination polymer as a strong electrochemiluminescent emitter for accurate and sensitive detection of tetracycline.

In this work, a self-luminescent micron europium cluster coordination polymer (Eu-CCP) cathode electrochemiluminescence (ECL) emitter is first reported. The mass percentage of Eu in Eu-CCP is 50.1%, indicating that Eu-CCP has a high-nucleation luminescence center. In addition, our Eu-CCP possesses a stable and efficient ECL red emission performance, and the intensity is approximately 6.5-fold higher than that of the traditional tris(2,2'-bipyridyl)ruthenium(II) dichloride. The enhancement of Eu-CCP luminescence in our system is due to the following reasons: (1) the mixed ligand and high nuclear europium luminescent center can cooperate to improve the quenching effect induced by water or hydroxyl groups; and (2) external coreaction accelerator and coreactant enhancement. We also investigate the application of Eu-CCP in ECL sensors by sensitive detection of tetracycline (TC). The low detection limit (73.5 fmol·L-1), high selectivity, good stability and satisfactory recoveries indicate that our ECL strategy can be used to detect TC accurately and sensitively.

Ratiometric fluorescent sensor based on europium (III)-functionalized covalent organic framework for selective and sensitive detection of tetracycline

Tetracycline (TC), a typical food contaminates, is of serious harmful impact toward human health. To explore simple methods for effective monitoring of TC-stained foods has extraordinary significance. Herein, we explored for the first time an europium (III)-functionalized fluorescent covalent organic framework (Dpy-TFPB-COF@Eu3+) via fixing Eu3+ onto a bipyridine-containing COF (Dpy-TFPB-COF) for ratiometric detection of TC in outstanding selectivity and sensitivity. In this sensor, Eu3+ performs as the recognition sites and specific response signal for TC, while Dpy-TFPB-COF is the fluorescent reference and shelter for Eu3+. Once TC is present, TC displaced water molecules to coordinate on Eu3+, and thereby generating remarkable fluorescence signal of Eu3+ based on sensitization mechanism, while the original fluorescence of Dpy-TFPB-COF remained. Profiting from its high porosity, the interaction between Dpy-TFPB-COF@Eu3+ and TC attained equilibrium only within 10 s. The detection limit of TC is achieved as ultralow as 7.5 nM. Based on these, lanthanide-based fluorescent COF was demonstrated as a ratiometric sensor toward TC with excellent selectivity and sensitivity, rapid response, self-calibration, and non-interference. This work not only exhibits fascinating performance of Eu3+-functionalized fluorescent COF toward the ratiometric sensing of TC, but also offers a prospective manner to explore various specific materials for multiple aims.

Dual-responsive ratiometric fluorescent sensor for tetracyclines detection based on europium-decorated copper nanoclusters

Development of accurate and efficient TCs residue analysis methods is of great significance for the protection of environment, food safety and public health. Herein, a dual-responsive ratiometric fluorescence sensor being capable of simple and sensitive detection of tetracycline (TC) was presented, which was constructed by immobilizing europium ions (Eu3+) onto the mercaptopropionic acid stabilized copper nanoclusters (MPA-Cu NCs). In the presence of TC, the red fluorescence of Eu3+ was enhanced through antenna effect (AE), while the green fluorescence of MPA-Cu NCs was quenched through internal filter effect (IFE), leading to an obvious fluorescence color evolution from green to red for the probe solution. In addition to successful design of a smartphone-assisted colorimetric analysis platform for portable detection, a logic gate device capable of intelligently monitoring TC concentration is also designed.

An Origami Paper‐Based Analytical Device Coupled with Fast‐Responding Functional RNA Superstructures for Tetracycline Detection

AbstractRapid and sensitive detection of tetracycline (TC) in the aquatic environment is important for the environmental ecosystem and human health. Herein, we presented on the first attempt to construct a fast‐responding gating system by using horseradish peroxidase (HRP)‐loaded functional RNA superstructures (HRP@3D RNA). Proteins were directly loaded into 3D RNA by the rolling circle transcription (RCT) reaction. We found that the specificity of aptamer‐ligand interaction could serve as a triggered manner to release the loaded HRP from 3D RNA. The above general scheme showed a few minutes of rapid release kinetics. According to the controlled‐release mechanism, we designed a disposable origami paper‐based analytical device (doPAD) coupled with HRP@3D RNA for colorimetric detection of TC. This doPAD can realize target recognition and signal readout by taking advantage of the unique spatial control advantages of 3D origami, thus generating a signal of color change that is positively related to the concentration of TC. This doPAD achieved the quantitative analysis of TC with a limit of detection of 10 nM within 41 min. We envision that the platform will be widely used in the field of environmental monitoring and biosensing.

Synthesis of a Dual Metal–Organic Framework Heterostructure as a Fluorescence Sensing Platform for Rapid and Sensitive Detection of Tetracycline in Milk and Beef Samples

Synthesis of a Dual Metal–Organic Framework Heterostructure as a Fluorescence Sensing Platform for Rapid and Sensitive Detection of Tetracycline in Milk and Beef Samples

Non-toxic fluorescent molecularly imprinted hydrogel based on wood-derived cellulose nanocrystals and carbon dots for efficient sorption and sensitive detection of tetracycline

For clean, effective, and high value-added use of wood, a novel non-toxic fluorescent molecularly imprinted hydrogel (FMIH) was prepared based on wood-derived cellulose nanocrystals and carbon dots for efficient sorption and sensitive detection of tetracycline (TC). The FMIH’s morphology, chemical structure, optical properties and non-cytotoxicity were investigated. The adsorption performance of FMIH toward TC was studied, indicating that the sorption data were well fitted by the Langmuir and Pseudo-second-order models, and the maximum sorption capacity was 544.4 mg/g. An evaluation of the detection performance of FMIH toward TC showed its excellent selectivity and sensitivity to TC with the detection limit of 0.11 μg/L. Mechanism analysis confirmed that the efficient sorption and sensitive detection was due to specific molecular recognition sites introduced by wood-derived cellulose nanocrystals and carbon dots. Moreover, a cost analysis performed for FMIH and commercial activated carbon (CAC) showed that the cost of removing 1 g of TC using FMIH was almost thirty-four times cheaper than that of CAC. This work could provide a new way for using wood to produce a low-cost, multifunctional, and green adsorbent for removing antibiotics.

An Up-conversion signal probe-MnO2 nanosheet sensor for rapid and sensitive detection of tetracycline in food

The irrational use of tetracycline (TC) poses a serious threat to human health, which calls for the development of efficient and reliable detection methods. Herein, an ideal sensor based on luminescence resonance energy transfer (LRET) between aptamer modified up-conversion nanoparticles as signal probes (donors) and manganese dioxide (MnO2) nanosheets (acceptors) was developed for TC detection in food samples. As a result of van der Waals forces between the nucleobases of the aptamer and the basal plane of MnO2 nanosheets, the distance of the donors and acceptors was shortened. The emission spectrum of the signal probes and the absorption spectrum of MnO2 nanosheets overlapped, resulting in LRET, and quenching of up-conversion luminescence. The TC-specific aptamer could fold into a complex conformational structure to provide recognition sites for TC. In the presence of TC, the aptamer was found to preferentially combine with TC due to the stacking of planar moieties, hydrogen bonding interactions and molecular shape complementarity, causing the separation of signal probes and nanosheets, and luminescence recovery. Consequently, a low detection limit of 0.0085 ng/mL was achieved with a wide detection range of 0.01–100 ng/mL. Moreover, the ability of the sensor to detect TC was confirmed in actual food samples and compared with the traditional ELISA with satisfactory results (p > 0.05).

An upconversion nanosensor for rapid and sensitive detection of tetracycline in food based on magnetic-field-assisted separation

Tetracycline, a broad-spectrum antibiotic, has been widely used in disease treatment and other fields. However, due to the unreasonable use, its residue remains in food which eventually harms human health. Here described an upconversion nanosensor for tetracycline detection based on magnetic separation and electrostatic adsorption. To identify tetracycline, tetracycline aptamer, and europium ions (Eu3+) were introduced in the system. According to the electrostatic adsorption principle, Eu3+ exposed core–shell UCNPs were bound to negative complex of magnetic nanoparticles (MNPs) and aptamer. In the presence of tetracycline, UCNPs separated with MNPs-aptamer and remained in the supernatant by an external magnetic field. Under optimal conditions, the linear detection range of tetracycline was 0.5–1000 ng·mL−1, and the detection limit was 0.17 ng·mL−1. It has been successfully applied to detect tetracycline in food samples. The constructed method provided broad prospects for tetracycline detection with the merits of simple operation, high sensitivity, excellent repeatability, and selectivity.

Europium Doped Silicon Quantum Dot As a Novel FRET Based Dual Detection Probe: Sensitive Detection of Tetracycline, Zinc, and Cadmium

The imbalance of Zn2+ /Cd2+ in the human body can lead to many serious diseases due to the overuse of antibiotics and deposition in animal products. Developing a functional material for detecting is challenging and in demand. Herein, silicon quantum dots (SiQDs) are designed as a functional platform for the detection of tetracycline and Zn2+ /Cd2+ . The COOH functionalized SiQDs with the emission wavelength of 450nm are chelated with Eu(NO3 )3 to form SiQDs-Eu3+ ratio fluorescent probes, which can be used to detect tetracycline (TCs) and Zn2+ /Cd2+ by fluorescence resonance energy transfer (FRET) principle sequentially. The fluorescent probe showed good linearity between ion concentration and fluorescence enhancement. The detection limit of TCs and Zn2+ /Cd2+ are 0.2 ×10-6 m and 3 ×10-6 m, respectively, when the pH of the solution is 7.4. In addition, the synthesized SiQDs-Eu3+ exhibited good stability (from 94.9% to 103.1%). The relative standard deviations (RSD, n= 10) of human serum and urine were both less than 3%. Therefore, the SiQDs-Eu3+ ratio fluorescence probe will provide a good application prospect in actual sample detection.

Label-free fluorescent sensor based on aptamer and thiazole orange for the detection of tetracycline

A label-free fluorescence aptasensor based on tetracycline-binding aptamers and thiazole orange (TO) was established for the selective and sensitive detection of tetracycline. TO is essentially nonfluorescent in aqueous solution, while TO can intercalate into the tetracycline-binding aptamers with G-quadruplex structures causing a high fluorescence emission intensity. In the presence of the target tetracycline, the specific recognition and binding of aptamers with the targets induce the conformational changes of aptamers from G-quadruplex structures to hairpin structures. Such target-induced conformational changes lead to the quenching of the fluorescence emission from TO, which thus constitutes the mechanism of the aptamer-based label-free fluorescence biosensor for specific target analysis. Under the optimum conditions, the proposed fluorescence assay shows a linear range from 0.05 to 100 μg mL−1 with a detection limit of 0.029 μg mL−1. The cross-reactivity of this approach against other common antibiotics was negligible compared with the response to tetracycline, proving the excellent selectivity of this label-free fluorescent aptasensor. When used in samples of tetracycline-spiked raw milk, this method demonstrated the satisfactory recoveries between 90.0% and 108.0%, and the results were in full agreement with those from HPLC, confirming the high reliability and feasibility of this bioassay for rapid screening of tetracycline in various practical applications. Using the structure-switching aptamers and the fluorescent intercalator of nucleic acids, the proposed label-free strategy avoids all complicated covalent modifications or chemical labeling, and thus offers obvious advantages of simplicity, convenience, specificity and cost efficiency.