Meng Cao,Feng Xu,Li Li,Honglian Zhang,Xin Liang,Tao Xu,Qian Li
The objective of this study was to establish a novel method for the detection of lean meat powder (salbutamol sulfate and terbutaline sulfate) residues in commercially available pig liver based on diazo coupling reaction by combining thin layer chromatography (TLC) with surface-enhanced resonance Raman scattering (SERRS). TLC was used to separate samples; after determining the spots of each component, diazo coupling reaction was carried out on the spots in situ to generate azo compounds, and then the spots of azo compounds mixed with silver sol on the TLC plate were qualitatively detected by SERRS. The limit of detection (LOD) of salbutamol sulfate was as low as 0.14 μg kg−1, and that of terbutaline sulfate was as low as 0.04 μg kg−1. The influence of the sample matrix in TLC-SERRS detection of salbutamol sulfate and terbutaline sulfate was investigated by experiment on a simulated positive sample, and salbutamol sulfate and terbutaline sulfate in commercially available pig liver were detected. Compared with the reported method (HPLC-MS/MS), this method has the advantages of strong specificity, high sensitivity, rapidity and low cost. It provides a new reference method for establishing and perfecting the safety system of veterinary drug residues.
Today’s rampant abuse of antibiotics and lean meat powder disturbs environment and threatens public human health. Therefore, fast in-site detection of antibiotics or lean meat powder residue could avoid potential risks. In this work, flexible graphene electrodes (FGE) were easily and facilely patterned and prepared by CO 2 laser at room environment, which was coupled with a portable electrochemical analyzer for electronic signal transmission. Laser-enabled flexible electrochemical sensor on finger can be used for rapid real-time in-site electrochemical identification of chloramphenicol (CAP), clenbuterol (CLB) and ractopamine (RAC) in meat. The electrochemical response of CAP, CLB and RAC is investigated with the limit of detection of 2.70, 1.29 and 7.81 μM and the linear range of 10–200, 5–80 and 25–250 μM in phosphate buffer saline (PBS) pH 7.0, correspondingly. The minimum detection concentrations of CAP, CLB and RAC were 20, 10 and 30 μM, respectively, in actual samples of pork. And the minimum detection concentrations of CAP, CLB and RAC were 10, 5 and 25 μM in milk, respectively. Such an integrated sensing platform enriches application of sensors on finger in food security and provides information that prevents drug containments from entering food chain.
Wang Zechun,Han Xinxin,Wang Ning,Wang Ruiyong,Chang Junbiao
Clenbuterol (CLB) is a notorious “lean meat essence”, which has harmful effects on human health. In this study, the binding of CLB to two proteins, human serum albumin (HSA) and the human fat mass and obesity associated protein (FTO), have been investigated by spectroscopic and molecular modeling methods. Fluorescence data revealed that CLB could bind to HSA (or FTO) to form a complex. Thermodynamic analysis and molecular modeling indicated that the binding process was a spontaneous molecular interaction procedure, in which hydrophobic interaction played a major role. Results indicated that CLB could lead to some microenvironmental changes of both proteins.
Runxian Li,Decheng Suo,Zhengjie Yu,Zhiming Xiao,Peiling Wei,Shi Wang,Yuchao Feng,Xia Fan
The abuse of illegal β2-adrenergic agonists in animal feeding poses a threat to human health. Fluorescent lateral flow immunoassay (LFIA) is a promising point-of-care testing (POCT) method for monitoring illicit drug use on farms. Here, a traffic light- dual-color quantum dot nanobeads based fluorescent lateral flow immunoassay (QBs-LFIA) was developed for simultaneously detecting ractopamine (RAC) and clenbuterol (CLE). CdSe/ZnS quantum dot nanobeads that emit red and green fluorescence were introduced in this study. They were conjugated with anti-RAC and anti-CLE monoclonal antibodies, respectively, to prepare traffic light fluorescent probes (QBs-mAbs). The dual-color QBs-mAbs greatly enhanced the analytical performance and solved the restriction that multiple mAbs on the control line cannot be accurately distinguished in traditional single-color LFIA. Under optimal conditions, the limits of detection (LODs) for RAC and CLE were 15.7 and 36.3 pg/mL, respectively. The recoveries in spiked cattle urine ranged from 80.3 to 106.1 % with relative standard deviations (RSDs) less than 13.2 %. Good correlations were observed between the detection results of QBs-LFIA and LC-MS/MS (R 2 = 0.9931). The proposed traffic light QBs-LFIA provides a novel approach for simultaneously detecting RAC and CLE. It is also a promising POCT platform for rapid, sensitive, and on-site detection of multiple drug residues.