Clenbuterol Research Articles

Determination of clenbuterol, salbutamol, and cimaterol in bovine retina by electrospray ionization-liquid chromatography-tandem mass spectrometry.

An electrospray ionization-liquid chromatography-tandem mass spectrometry (ESI/LC/MS/MS) method was developed for the simultaneous determination of the beta-agonists clenbuterol, salbutamol, and cimaterol in bovine retina. The tissue was homogenized in alkaline buffer and spiked to give 10, 15, and 20 ng/g each of the 3 analytes together with the internal standards d6-salbutamol and d6-clenbuterol. The mixture was incubated with protease enzyme to release any protein-bound analytes and then made alkaline before extraction with isobutanol. The extract was dissolved in water and transferred to a clenbuterol immunoaffinity column. After washing, the analytes were eluted and analyzed by ESI/LC/MS/MS using a C18 column with acetic acid-methanol as mobile phase. No interferences were observed from the spiked retina extract at the various single-reaction monitoring modes. Average recoveries for clenbuterol, salbutamol, and cimaterol were 94, 85, and 87% with coefficients of variation (CVs) of 9.4, 9.9, and 8.6%, respectively. A correlation coefficient of r2 = 0.9999 was obtained for all analytes. The limits of detection for clenbuterol, salbutamol, and cimaterol, determined from 3 times the standard deviation of 7 replicates of the lowest spike, were 2.5, 3.5, and 2.0 ng/g with CVs of 8.9, 11.6, and 7.2%, respectively.

Construction, expression and functional analysis of anti-clenbuterol codon-optimized scFv recombinant antibody

The construction, expression and functional analysis of codon-optimized single-chain variable fragment (coscFv) against clenbuterol (CBL) prepared from the Escherichia coli system is described. First, the ionic concentration for coscFv expression was optimized through single-factor experiments. Then, the extraction conditions of inclusion bodies were optimized, and coscFv was affinity-purified. Finally, the functional analysis of coscFv was elucidated by indirect competitive enzyme-linked immunosorbent assay (icELISA) and molecular docking. After optimizing the ionic concentration, the yield of coscFv increased from 21.69% to 23.26%. The molecular weight of coscFv was determined to be approximately 27 kDa according to the SDS-PAGE and Western blot assay. The percentage of coscFv was as high as 43.9% after the inclusion bodies were extracted, washed, and dissolved. Functional analysis indicated that the coscFv recognized CBL, and the 50% inhibition average concentration of CBL (IC50) was 4.22 ± 0.01 (n = 3) ng/mL. The binding site between coscFv and CBL consisted of Asp33H, Met34H, Ser50H, Arg52H, Tyr57H, Leu59H, Asp99H, and Tyr93L. Our study confirms that coscFv can bind with CBL through the key amino acid residues and can be used to sensitively detect CBL.

Simultaneous Detection of Multiple β-Adrenergic Agonists with 2-Directional Lateral Flow Strip Platform.

Clenbuterol (CL), salbutamol (SAL) and ractopamine (RAC) are the three common β-adrenergic agonists, which are the main hazards in food safety and affect human health through the food chain. A convenient and efficient method is urgently required to perform on-site detection of multiple β-adrenergic agonists to avoid frequent poisoning incidents. In this paper, a 2-directional lateral flow strip technique (2-directional LFS) is developed for rapid and simultaneous detection of CL, SAL and RAC with single sampling. Compared to the conventional lateral flow strip, this 2-directional LFS technique can realize simultaneous detection of three or more target analytes without any change of intrinsic simplicity of LFS. Furthermore, this 2-directional LFS can effectively avoid the potential intrinsic cross-reactivity among the reagents to analogues. Under the optimized conditions, CL, SAL and RAC were all successfully determined with satisfactory results in both buffer and urine samples with the detection limit as low as 0.5 ng/mL. This 2-directional LFS technique can revolutionize the commercial single-analyte LFS products and can effectively widen the applications of the classic LFS in various fields.

Thyrotoxicosis Involves β2-Adrenoceptor Signaling to Negatively Affect Microarchitecture and Biomechanical Properties of the Femur.

Background: Thyrotoxicosis increases bone turnover, resulting in net bone loss. Sympathetic nervous system (SNS) activation, via β2-adrenoceptor (β2-AR) signaling, also has osteopenic effects. Because thyroid hormones (TH) interact with the SNS to regulate several physiological processes, we hypothesized that this interaction also occurs to regulate bone mass. Previous studies support this hypothesis, as α2-AR knockout (KO) mice are less susceptible to thyrotoxicosis-induced osteopenia. Here, we evaluated whether TH-SNS interactions in bone involve β2-AR signaling. Methods: Thyrotoxicosis was induced in 120-day-old female and male mice with β2-AR gene inactivation (β2-AR-/-) by daily treatment with supraphysiological doses of triiodothyronine (T3) for 12 weeks. The impact of thyrotoxicosis on femoral bone microarchitecture, remodeling, fracture risk, and gene expression of the receptor activator of nuclear factor-kappa-B (RANK)-RANK ligand (RANKL)-osteoprotegerin (OPG) pathway was evaluated. In addition, the effect of the β2-AR-specific agonist clenbuterol (CL) on cAMP accumulation was determined in osteoblastic (MC3T3-E1) cells treated with T3 and/or 17β-estradiol (E2). Results: Thyrotoxicosis negatively affected trabecular bone microarchitecture in wild-type (WT) females, but this effect was milder or nonexistent in β2-AR-/- animals, whereas the opposite was seen in males. T3 treatment increased the femoral RANKL/OPG mRNA ratio and the endosteal perimeter and medullary area of the diaphysis in WT females and males, but not in β2-AR-/- mice, suggesting that T3 promotes endosteal resorption in cortical bone, in a mechanism that involves β2-AR signaling. T3 treatment increased endocortical mineral apposition rate only in WT females but not in β2-AR-/- mice, suggesting that TH also induce bone formation in a β2-AR signaling-dependent mechanism. T3 treatment decreased femoral resistance to fracture only in WT females, but not in KO mice. E2 and CL similarly increased cAMP accumulation in MC3T3-E1 cells; whereas T3 alone had no effect, but it completely blocked E2-stimulated cAMP accumulation, suggesting that some T3 effects on bone may involve E2/cAMP signaling in osteoblasts. Conclusions: These findings sustain the hypothesis that T3 interacts with the SNS to regulate bone morphophysiology in a β2-AR signaling-dependent mechanism. The data also reveal sex as an important modifier of skeletal manifestations of thyrotoxicosis, as well as a modifier of the TH-SNS interactions to control bone microarchitecture, remodeling, and resistance to fracture.

A novel murine antibody and an open sandwich immunoassay for the detection of clenbuterol

Clenbuterol (CLEN) is a sympathomimetic amine used as a decongestant and bronchodilator while treating breathing disorders. It is also used in food-producing animals as it improves the rate of red meat production. However, it is prohibited in many countries nowadays due to human health and safety concerns. Unfortunately, the illegal use of CLEN is still rampant. Thus, monitoring it in food and livestock is important. Here, we report a novel murine antibody and an open sandwich enzyme linked immunosorbent assay (OS-ELISA) to detect CLEN based on antigen-antibody reactions. The genes of antibody variable regions in mice immunized with CLEN conjugated with bovine serum albumin were cloned into a phagemid (pDong1/Fab) to construct a phage-display antibody library, from which a novel antibody, A12, was selected. Then, an OS-ELISA was developed to detect CLEN using separated variable regions of the A12 antibody. The limit of detection of the assay was found to be 8 ng/mL, which was useful for monitoring CLEN usage.

Visualization and colorimetric determination of clenbuterol in pork by using magnetic beads modified with aptamer and complementary DNA as capture probes, and G-quadruplex/hemin and DNA antibody on the metal-organic framework MIL-101(Fe) acting as a peroxidase mimic.

A visualization strategy is described for the detection of clenbuterol (CLB). It is using of antibody against dsDNA and G-quadruplex/hemin labeled on a metal organic framework of type MIL-101(Fe) (G-quadruplex/hemin-anti-DNA/MIL-101) acting as a peroxidase mimetic, and magnetic beads modified with aptamer and complementary DNA (MB/Apt-cDNA) as capture probes. The detection reagent was prepared via the reactions between the double stranded DNA (Apt-cDNA) in capture probes and anti-DNA in peroxidase mimetic. In the presence of CLB, the aptamer on the magnetic beads preferentially binds CLB, and the peroxidase mimetic is released to the supernatant after magnetic separation. The released peroxidase mimetic can catalyze the TMB/H2O2 chromogenic system under mild conditions. This leads to the development of a blue-green coloration whose absorbance is measured at 650nm. The detection limit is as low as 34 fM of CLB. The method was applied to the determination of CLB in pork samples and gave results that were consistent with data obtained with an ELISA kit. Graphical abstract A visualization strategy is described for the detection of clenbuterol. The selectivity of detection system for clenbuterol is excellent compared with other interferents. The method was applied to the determination of CLB in pork samples.

QuEChERS Purification with HPLC-MS/MS for Rapid Confirmation in Acute Clenbuterol Poisoning Case Sample

QuEChERS Purification with HPLC-MS/MS for Rapid Confirmation in Acute Clenbuterol Poisoning Case Sample

A silica nanoparticle based 2-color immunochromatographic assay for simultaneous determination of clenbuterol and ractopamine

An immunochromatographic assay (ICA) is presented that can be applied to simultaneous detection of clenbuterol (CLE) and ractopamine (RAC). It is making use of two red and blue silica nanoparticles (SiNPs) that act as labels for encoding the antibodies. This design permits multiplexed analysis in a single test line and does not require an external source for photoexcitation. Anti-CLE was labeled with red SiNPs, and anti-RAC with blue SiNPs. The capture antigens CLE-BSA and RAC-BSA were placed onto the conjugate pad and the test line of the test strip, respectively. Under bare eye examination, no cross-colored lines or nonspecific bioconjugate adsorption were observed, and the visible limit of detections for CLE (red) and RAC (blue) are 3 and 2ng‧mL-1, respectively. This design allows for multiplexed detection with reduced device dimensions and costs, and with easy integration and manufacturing. Conceivably, the method may be extended to simultaneous determination of numerous other analytes. Graphic abstract The principle of qualitative detection strategy of multiplex immunochromatographic assay for clenbuterol (CLE) and ractopamine (RAC) is schematically illustrated. Depending on the type and ratio of organic dyes, the color of colored silica nanoparticle can be tuned from red to purple and even to black (lower right corner).

Integrated immunochromatographic assay for qualitative and quantitative detection of clenbuterol

In this study, colloidal gold (CG) and time-resolved fluorescent nanobead (TRFN) probes were used to establish an integrated immunochromatographic assay (ICA) to qualitatively and quantitatively detect clenbuterol (CLE). The best experimental conditions for the two probes in separate ICAs were obtained by optimizing the antibody labeling concentration, the amount of antigen, and the concentration of probe. When the CG and TRFN probes co-existed in the ICA, the latter had no effect on the sensitivity of qualitative detection of the CG probe-based ICA. However, the CG probe optimized the linear range of quantitative detection in the TRFN probe-based ICA. The integrated test strip can be used for qualitative and quantitative detection of CLE in one step. When the amount of antigen reached 0.4 mg/mL, the CG probe concentration reached 1.2 μg/mL, and the TRFN probe concentration reached 0.68 μg/mL. The qualitative sensitivity of the integrated ICA was 0.5 ng/mL and its quantitative limit of detection was 0.04 ng/mL with a detection range of 0.1–2.7 ng/mL. This developed method is of great significance for large-scale samples screening and positive monitoring in the field of food safety testing.

Role of β-adrenergic signaling in masseter muscle.

In skeletal muscle, the major isoform of β-adrenergic receptor (β-AR) is β2-AR and the minor isoform is β1-AR, which is opposite to the situation in cardiac muscle. Despite extensive studies in cardiac muscle, the physiological roles of the β-AR subtypes in skeletal muscle are not fully understood. Therefore, in this work, we compared the effects of chronic β1- or β2-AR activation with a specific β1-AR agonist, dobutamine (DOB), or a specific β2-AR agonist, clenbuterol (CB), on masseter and cardiac muscles in mice. In cardiac muscle, chronic β1-AR stimulation induced cardiac hypertrophy, fibrosis and myocyte apoptosis, whereas chronic β2-AR stimulation induced cardiac hypertrophy without histological abnormalities. In masseter muscle, however, chronic β1-AR stimulation did not induce muscle hypertrophy, but did induce fibrosis and apoptosis concomitantly with increased levels of p44/42 MAPK (ERK1/2) (Thr-202/Tyr-204), calmodulin kinase II (Thr-286) and mammalian target of rapamycin (mTOR) (Ser-2481) phosphorylation. On the other hand, chronic β2-AR stimulation in masseter muscle induced muscle hypertrophy without histological abnormalities, as in the case of cardiac muscle, concomitantly with phosphorylation of Akt (Ser-473) and mTOR (Ser-2448) and increased expression of microtubule-associated protein light chain 3-II, an autophagosome marker. These results suggest that the β1-AR pathway is deleterious and the β2-AR is protective in masseter muscle. These data should be helpful in developing pharmacological approaches for the treatment of skeletal muscle wasting and weakness.

Simultaneous determination of β-agonists by UHPLC coupled with electrochemical detection based on palladium nanoparticles modified BDD electrode

Palladium nanoparticles (PdNPs) modified boron-doped diamond (BDD) electrode was simply fabricated via electrodeposition technique for the sensitive electro-analysis of four β-agonist compounds, including terbutaline (TER), salbutamol (SAL), ractopamine (RAC), and clenbuterol (CLB) after a prior separation by ultra-high performance liquid chromatography (UHPLC). The separation was carried out using a reverse phase C18 column with gradient elution of appropriate proportion between methanol and phosphate buffer solution (PBS) pH7.0 at a flow rate of 1.0minmL−1. The following electrochemical detection (ECD) was accomplished by amperometric method with a detection potential of 1.0V vs Ag/AgCl. The modified BDD electrode, unlike other carbon-based electrodes used for β-agonists detection, typically showed the superior anti-fouling ability and provided excellent long-term stability, resulting in no complicated cleaning steps needed during each determination. The measurement of β-agonists using the PdNPs modified BDD electrode integrated with UHPLC showed a linear relationship in the range of 0.2 to 200μgmL−1 with detection limits of 0.04, 0.02, and 0.03μgmL−1 for TER, SAL, and RAC, respectively. Meanwhile, CLB displayed linearly in the range of 0.5 to 200μgmL−1 with a detection limit of 0.19μgmL−1. Moreover, this method was successfully applied to detect β-agonists in diverse samples, including swine feed, swine meat, and human urine with satisfied recoveries in the range from 80.5% to 110.0%. Reliability of this developed method was also validated with ultra-high performance liquid chromatography coupled with ultra-violet detection (UHPLC-UV), and the results showed highly quantitative agreement between the two methods. Therefore, the PdNPs modified BDD could be productively utilized as effective electrodes, with good electrocatalytic activity of PdNPs towards β-agonists oxidation and favorable anti-fouling performance of BDD. The simultaneous detection of four β-agonists by UHPLC-ECD exhibited good stability, acceptable reusability, high sensitivity and rapid analysis.

Immunochromatographic fluorometric determination of clenbuterol with enhanced sensitivity.

A method is described to enhance the sensitivity of an immunochromatographic assay for clenbuterol (CLE) by making use of dually-labeled gold nanoparticles (GNPs), background fluorescence blocking, and immunomagnetic separation. The GNPs were labeled with biotinylated antibody and streptavidin, respectively, and dually labeled GNPs were obtained via the biotin-streptavidin interaction to amplify the detection signal. The fluorescent signal was blocked by dually labeled GNPs and decreased as the dually labeled GNPs aggregation increases on nitrocellulose membrane, which derived from fluorescent polyvinylchloride card. However, fluorescence (measured at excitation/emission wavelengths of 518/580 nm)recovers when CLE reacts with dually labeled GNPs. Immunomagnetic separation was first applied for sample pretreatment. This can offset the matrix effect and improves the sensitivity and accuracy of the assay. Under the optimal conditions, the limits of detection of CLE visually were 0.25μg·L-1. In addition, clenbuterol can be quantified in swine urine with a 0.03μg·L-1 detection limit. This is 60-fold lower than current immunochromatography. Response is linear in the 0.06-0.59μg·L-1 concentration range, and the recoveries from spiked swine urine range from 81 to 115%." Graphical abstract Schematic presentation of the strategies for improving sensitivity of immunochromatographic assay. It includes immunomagnetic separations, dually-labeled gold nanoparticles and background fluorescence blocking. The assay was applied to detect clenbuterol (CLE) in swine urine with an excellent performance.

An ultrasensitive sensor based on polyoxometalate and zirconium dioxide nanocomposites hybrids material for simultaneous detection of toxic clenbuterol and ractopamine

A new electrochemical sensor based on isopolyacid anions (NH4)5PV8Mo4O40 (NPVMo) and transition metal zirconium dioxide (ZrO2) nanocomposites was prepared in double signal amplification for the simultaneous detection of clenbuterol (CLB) and ractopamine (RAC). This is the first time that ZrO2 was used as POM carrier to prepare electrochemical sensor. Scanning electron microscopic (SEM), nitrogen adsorption/desorption isotherms and X-ray diffraction (XRD) test showed that the synthesized ZrO2 nanoparticles have a needlelike nanostructure and a larger surface area. The electrochemical measurements such as cyclic voltammetry (CV), amperometric and differential pulse voltammetry (DPV) indicated that the NPVMo/ZrO2/GCE exhibited much high stability, fast response, good conductivity and electrocatalytic actives, which enhanced peak current and negatively shifted the oxidation potentials of CLB and RAC. Due to the synergistic action between NPVMo and ZrO2 nanoparticles, DPV results showed that the oxidation of CLB and RAC on NPVMo/ZrO2/GCE could be detected selectively and sensitively with low limits of detection, 5.03 × 10−9 mol L−1 for CLB and 9.3 × 10−7 mol L−1 for RAC, and a wide range for calibration curves of CLB and RAC from 0.1 to 1000 μM and 3.0 to 50 μM, respectively. In addition, the proposed sensor was applied to detect content of CLB and RAC in pork sample, and the recovery was over the range from 94.4 to 102.3%.

Response to Clenbuterol in Humans

Response to Clenbuterol in Humans

Immunoassay of clenbuterol with bacteria as natural signal carriers for signal amplification

Many food safety hazard factors pose a great threat to human health. To mornitor these factors, development of a sensitive, reliable, and efficient detection platform is significantly important. Herein, a sensitive indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was developed, in which bacteria was introduced as natural signal carriers to construct probes. Through the carriers, the ratio between signal and recognition molecules was flexibly adjusted. As is known, in the competitive immunoassay, the limited number of antibodies was key to significantly improved sensitivity. By this protocol, horseradish peroxidase (HRP) was enriched on the bacterial surface to realize signal amplification, extremely reduce the applied quantity of antibody, and finally trigger intense competition between free target analytes and immobilized antigen. Clenbuterol (CL) as a model target was analyzed by the proposed biosensor system, with a linear range of 0.02–1.0 ng mL−1 and a sensitivity (expressed as IC50) of 0.16 ng mL−1. This contribution has opened up a new route to improve analytical performance of ic-ELISA and provided an application prospect in the detection of other small molecule targets.

Computer-Aided Design of Molecularly Imprinted Polymers for Simultaneous Detection of Clenbuterol and Its Metabolites.

Molecular imprinting technology (MIT) offers an effective technique for efficient separation and enrichment of specific analytes from complicated matrices and has been used for illicit veterinary drug detectionin recent years due to its high selectivity, good chemical stability, and simple preparation. The development of in silico-based approaches has enabled the simulation of molecularly imprinted polymers (MIPs) to facilitate the selection of imprinting conditions such as template, functional monomer, and the best suitable solvent. In this work, using density functional theory (DFT), the molecularly imprinted polymers of clenbuterol and its metabolites were designed by computer-aided at B3LYP/6-31 + G (d, p) level. Screening molecular imprinting components such as functional monomers, cross-linkers, and solvents has been achieved in the computational simulation considerations. The simulation results showed that methacrylic acid (MAA) is the best functional monomer; the optimal imprinting ratio for both clenbuterol (CLB) and its dummy template molecule of phenylephrine (PE) to functional monomer is 1:3, while the optimal imprinting ratio for the two dummy template molecules of CLB’s metabolites is 1:5. Choosin gethyleneglycol dimethacrylate (EDGMA) as a crosslinker and aprotic solvents could increase the selectivity of the molecularly imprinted system. Atoms in Molecules (AIM) topology analysis was applied to investigate the template-monomer complexes bonding situation and helped to explain the nature of the reaction in the imprinting process. These theoretical predictions were also verified by the experimental results and found to be in good agreement with the computational results. The computer-simulated imprinting process compensates for the lack of clarity in the mechanism of the molecular imprinting process, and provides an important reference and direction for developing better recognition pattern towards CLB and its metabolite analytes in swine urine samples at the same time.

Development of Highly Sensitive Immunosensor for Clenbuterol Detection by Using Poly(3,4-ethylenedioxythiophene)/Graphene Oxide Modified Screen-Printed Carbon Electrode.

Clenbuterol (CLB) is an antibiotic and illegal growth promoter drug that has a long half-life and easily remains as residue and contaminates the animal-based food product that leads to various health problems. In this work, electrochemical immunosensor based on poly(3,4-ethylenedioxythiophene)/graphene oxide (PEDOT/GO) modified screen-printed carbon electrode (SPCE) for CLB detection was developed for antibiotic monitoring in a food product. The modification of SPCE with PEDOT/GO as a sensor platform was performed through electropolymerization, while the electrochemical assay was accomplished while using direct competitive format in which the free CLB and clenbuterol-horseradish peroxidase (CLB-HRP) in the solution will compete to form binding with the polyclonal anti-clenbuterol antibody (Ab) immobilized onto the modified electrode surface. A linear standard CLB calibration curve with R2 = 0.9619 and low limit of detection (0.196 ng mL−1) was reported. Analysis of milk samples indicated that this immunosensor was able to detect CLB in real samples and the results that were obtained were comparable with enzyme-linked immunosorbent assays (ELISA).

Simultaneous determination of β-agonists on hexagonal boron nitride nanosheets/multi-walled carbon nanotubes nanocomposite modified glassy carbon electrode

β-Agonists are illegally consumed in various products such as food and animal and effect the nutrition distribution owing to change of body fat. In addition, they result in acute poisoning and several symptoms such as muscular tremors and nervousness. A new electrochemical approach based on two-dimensional hexagonal boron nitride (2D-hBN) nanosheets decorated functionalized multi-walled carbon nanotubes (f-MWCNTs) was presented for simultaneous determination of β-agonists such as phenylethanolamine A (PEA), clenbuterol (CLE), ractopamine (RAC) and salbutamol (SAL) in urine samples. X-ray diffraction (XRD) method, Raman spectroscopy, scanning electron microscope (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used characterizations of nanomaterials. After that, 2D-hBN/f-MWCNTs nanocomposite modified glassy carbon electrode (GCE) was prepared for simultaneous determination of β-agonists. 1.0 × 10−12–1.0 × 10−8 M and 1.0 × 10−13 M were founded as the linearity range and the detection limit (LOD) for PEA, CLE, RAC and SAL. Finally, the prepared electrochemical sensor was used for urine sample analysis in presence of ascorbic acid (AA) and uric acid (UA).

A highly stable black phosphorene nanocomposite for voltammetric detection of clenbuterol.

A nanocomposite was prepared from graphene-like two-dimensional black phosphorene (BP, an allotrope of phosphorus) and nafion (Nf) treated with isopropanol (IP). A glassy carbon electrode (GCE) modified with this nanocomposite was found to be a viable sensor for voltammetric determination of clenbuterol (CLB). Unlike previously reported pure BP, the BP nanocomposite was stable towards water and oxygen. Its morphology, structure, electrochemically active surface area and electrochemical stability were investigated. The BP-Nf (IP) modified GCE displayed good electrochemical stability and electrocatalytic capacity with a low working potential of 0.94V (vs. SCE), excellent peak current response for CLB in a linear concentration range of 0.06-24μM with a detection limit of 3.7nM (3σ/m) and a sensitivity of 0.14μA·μM-1·cm-2 under optimal conditions. A sensing mechanism for the electro-oxidation of CLB was suggested and verified by density functional theory calculations under imitation of aqueous solution conditions. The sensor was successfully applied to the determination of CLB in bovine meat and bovine serum samples. Graphical abstract Highly-stable black phosphorene (BP) nanocomposite based on Nafion (Nf) was used to modify a glassy carbon electrode (GCE). It is shonw to be a viable electrochemical platform for sensitive voltammetric determination of trace clenbuterol (CLB) in bovine beef and bovine serum.

A signal-on electrochemiluminescence sensor for clenbuterol detection based on zinc-based metal-organic framework-reduced graphene oxide-CdTe quantum dot hybrids.

Clenbuterol (CLB) is harmful to human health when used long term, and it has been listed by the World Anti-Doping Agency (WADA). In this work, a novel zinc-based metal-organic frameworks-reduced graphene oxide-CdTe quantum dots (ZnMOF-RGO-CdTe QDs) hybrid was used to construct an electrochemiluminescence (ECL) sensor for detecting CLB. CdTe QDs, loaded by RGO, exhibited an enhanced ECL signal. In addition, the ZnMOFs catalyzed OH• generation by coreactant H2O2, which further strengthened the ECL signal of the CdTe QDs. The integration of ZnMOFs and RGO-CdTe QDs endowed the sensor with high sensitivity for CLB detection. The intensity of the ECL signal increased as the concentration of CLB increased. The linear range of CLB detection was 3.0 × 10-13M to 6.0 × 10-10M, and the detection limit was estimated to be 1.0 × 10-13M. Furthermore, the sensor displayed a good repeatability and stability. The ZnMOF-RGO-CdTe QD hybrids described in this study provide a foundation for the development of new methods of detecting CLB. Graphical abstract ᅟ.