Rapid detection of chloramphenicol residues in aquatic products using colloidal gold immunochromatographic assay

Green and cost-effective voltammetric assay for spiramycin based on activated glassy carbon electrode and its applications to urine and milk samples

A simple, cost-effective, and efficient differential pulse voltammetric (DPV) assay for monitoring spiramycin adipate (SPA) in its dosage forms, urine, and milk samples at an activated glassy carbon electrode (GCE) was developed. GCE was electrochemically activated by anodization at a high positive voltage (2.5 V). The activated glassy carbon electrode (AGCE) was surface characterized, optimized, and utilized for the electrochemical assay of SPA. The electrochemical behavior of the AGCEs was investigated using cyclic voltammetry (CV) which shows a remarkable increase in the anodic peak of SPA in comparison with GCE. This behavior reflects a remarkable increase in the electrocatalytic oxidation of SPA at AGCE. The impacts of various parameters such as scan rate, accumulation time, and pH were investigated. The analytical performance of the activated glassy carbon electrodes was studied utilizing DPV. Under optimum conditions, the oxidation peak current exhibited two linear ranges of 80 nm to 0.8 μM and 0.85-300 μM with a lower limit of detection (LOD) of 20 nM. The developed assay exhibited high sensitivity, excellent repeatability, and good selectivity. Additionally, the developed SPA-sensitive modified GCE was successfully applied for SPA assay in its pharmaceutical dosage form and diluted biological fluids as well, with satisfactory recovery results which correlated well with the results obtained using spectrophotometry.

A rapid and reliable immunochromatographic strip for detecting paraquat poinsoning in domestic water and real human samples

Paraquat (PQ) is one of the most commonly used herbicides, but it has polluted the environment and threatened human health through extensive and improper usage. Here, a new naked-eye PQ immunochromatographic strip was developed to recognize PQ in domestic water and real human samples within 10 min based on a novel custom-designed anti-PQ antibody. The PQ test strip could recognize PQ at a concentration as low as 10 ng/ml, reaching the high-efficiency time-of-flight mass spectrometry detection level and identifying trace amounts of PQ in samples treated with a diquat (DQ) and PQ mixture. Notably, both the performance evaluation and clinical trial of the proposed PQ strips were validated in multiple hospitals and public health agencies. Taken together, our study firstly provide the clinical PQ-targeted colloidal gold immunochromatographic test strip designed both for environment water and human sample detection with multiple advantages, which are ready for environmental monitoring and clinical practice.

Antibiotic Use in Livestock and Residues in Food-A Public Health Threat: A Review

The usage of antibiotics has been, and remains, a topic of utmost importance; on the one hand, for animal breeders, and on the other hand, for food safety. Although many countries have established strict rules for using antibiotics in animal husbandry for the food industry, their misuse and irregularities in compliance with withdrawal periods are still identified. In addition to animal-origin foods that may cause antibiotic residue problems, more and more non-animal-origin foods with this type of non-compliance are identified. In this context, we aim to summarize the available information regarding the presence of antibiotic residues in food products, obtained in various parts of the world, as well as the impact of consumption of food with antibiotic residues on consumer health. We also aim to present the methods of analysis that are currently used to determine antibiotic residues in food, as well as methods that are characterized by the speed of obtaining results or by the possibility of identifying very small amounts of residues.

Rapid quantitative detection of chloramphenicol in three food products by lanthanide-labeled fluorescent-nanoparticle immunochromatographic strips

A rapid and sensitive fluorescence-based immunochromatographic test (ICT) was successfully developed to determine chloramphenicol (CAP) levels in three food products. In this method, lanthanide fluorescent microspheres were used as a label to detect CAP in food samples within 30 min quantitatively, and the result was displayed on the test strip reader. After optimizing detection conditions, the detection limit (LOD) for the three food products was 0.048-0.073 ng g^-1, and the half-maximal inhibitory concentration (IC₅₀) was 0.27 ng mL^-1. Six other veterinary drugs were detected using the test strip, and no cross-reactivity was observed, indicating that the specificity of the method was satisfactory. This method was also successfully applied to determine CAP in honey, egg, and fish samples, with recoveries ranging from 78.73% to 121.12%. The results demonstrated that this test strip had high sensitivity and specificity, and could be used for field detection within 30 min.

Development and perspectives of rapid detection technology in food and environment

Food safety become a hot issue currently with globalization of food trade and food supply chains. Chemical pollution, microbial contamination and adulteration in food have attracted more attention worldwide. Contamination with antibiotics, estrogens and heavy metals in water environment and soil environment have also turn into an enormous threat to food safety. Traditional small-scale, long-term detection technologies have been unable to meet the current needs. In the monitoring process, rapid, convenient, accurate analysis and detection technologies have become the future development trend. We critically synthesizing the current knowledge of various rapid detection technology, and briefly touched upon the problem which still exist in research process. The review showed that the application of novel materials promotes the development of rapid detection technology, high-throughput and portability would be popular study directions in the future. Of course, the ultimate aim of the research is how to industrialization these technologies and apply to the market.

Polycaprolactone/silk fibroin electrospun nanofibers-based lateral flow test strip for quick and facile determination of bisphenol A in breast milk

This study aimed to develop a sensitive lateral flow test strip for the detection of bisphenol A (BPA) in breast milk. Conventional nitrocellulose test membrane was coated with the coaxial nanofiber, consisting of the inner polycaprolactone (PCL) and the outer PCL/silk fibroin (SF) mixture, to decrease the flow rate of the breast milk in the lateral flow assay (LFA). The nanofiber was prepared by using coaxial electrospinning, and BPA antibody was immobilized physically to the nanofiber. This nanofiber was used as a test membrane in the LFA. Color changes on the test membrane were evaluated as the signal intensity of the BPA. Breast milk creates a background on surfaces due to its structural properties. This background was detected by comparing the signal intensity with the signal intensity of water. The higher signal intensity was found in water samples when compared to breast milk samples. Although the detection limit is 2 ng/ml in both coaxial PCL/SF nanofiber and nitrocellulose (NC) test membranes, the color intensity increased with the increasing BPA concentration in the coaxial PCL/SF nanofiber. As a new dimension, the coaxial PCL/SF nanofiber provided higher color intensity than the NC membrane. In conclusion, a sensitive onsite method was developed for the detection of BPA in breast milk by using new coaxial PCL/SF nanofiber as a test membrane in LFA.

Visible and eco-friendly immunoassays for the detection of cyclopiazonic acid in maize and rice

Cyclopiazonic acid (CPA) is an indole-tetramine mycotoxin commonly produced by Penicillium and Aspergillus and is widely found in agricultural products, fermented food, and feed. Food contaminated with CPA poses a substantial health risk to consumers. Therefore, eco-friendly immunoassays, including an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and a lateral flow immunochromatographic strip (LFICS), were developed to monitor CPA in maize and rice samples. For this purpose, a monoclonal antibody (3H12) posed highly resistant to pH (5.6 to 9.6) and ethanol (≤50%) was generated by mouse immunization. Negative maize and rice samples or samples spiked with CPA were extracted with ethanol/0.01 M sodium borate buffer (4/1, v/v, pH 8.4). For ic-ELISA analysis, the limits of detection (LODs) were 0.48 and 0.28 ng/g for maize and rice samples, respectively. The recovery for spiked maize was 76.9% to 83.5% with the highest variable coefficient (CV_max ) being 9.32%. For spiked rice, the recovery was 85.3% to 105.1% with a CV_max of 8.56%. For LFICS analysis, the visible LODs were 2.5 and 1 ng/g and cutoff values were 5 and 2.5 ng/g for maize and rice samples, respectively. The LFICS method gave results within 5 to 10 min, providing an auxiliary analytical tool for the rapid, sensitive, and portable screening of the massive samples onsite.

Quantitative and rapid detection of amantadine and chloramphenicol based on various quantum dots with the same excitations

Herein, we developed a sensitive and quantitative flow assay for simultaneous detection of amantadine (AMD) and chloramphenicol (CAP) in chicken samples based on different CdSe/ZnS quantum dots (QDs). In contrast to other reports, the QDs could be excited by the same excitations that lowered the requirements for the matching instruments. Under the optimal conditions, the strategy permitted sensitive detection of AMD and CAP in a linear range of 0.23 to 1.02 ng/g and 0.02 to 0.66 ng/g. The limits of detection were 0.18 ng/g and 0.016 ng/g, respectively. Moreover, the whole detection process could be completed within 20 min with no additional sophisticated instruments and complicated operations. Spiked samples were analyzed using both QD-based lateral flow immunoassay (QD-LFIA) and commercial ELISA kits with good correlation (R² = 0.96). Moreover, this study laid the foundation and simplified the development of the requisite instrument. Graphical abstract ᅟ.

Removal of Chloramphenicol from Aqueous Solution Using Low-Cost Activated Carbon Prepared from Typha orientalis

Low-cost and efficient activated carbon (AC) was prepared from Typha orientalis via phosphoric acid activation for chloramphenicol (CAP) removal. The adsorption capacity and mechanisms of CAP on AC were investigated. The physicochemical properties of AC were characterized by an N2 adsorption/desorption isotherm, elemental analysis, Boehm’s titration and X-ray photoelectron spectroscopy (XPS). The effects of experimental parameters were investigated to study the adsorption behaviors of CAP on AC, including contact time, initial concentration, ionic strength, and initial pH. AC had a micro-mesoporous structure with a relatively large surface area (794.8 m2/g). The respective contents of acidic and basic functional groups on AC were 2.078 and 0.995 mmol/g. The adsorption kinetic that was well described by a pseudo-second-order rate model implied a chemical controlling step. The adsorption isotherm was well fitted with the Freundlich isotherm model, and the maximum CAP adsorption capacity was 0.424 mmol/g. The ionic strength and pH had minimal effects on CAP adsorption. The dominant CAP adsorption mechanisms on AC were evaluated and attributed to π-π electron-donor-acceptor (EDA) interaction, hydrophobic interaction, in conjunction with hydrogen-bonding interaction. Additionally, AC exhibited an efficient adsorption performance of CAP in a realistic water environment.

A Rapid and Semi-Quantitative Gold Nanoparticles Based Strip Sensor for Polymyxin B Sulfate Residues

Increasing attention is now being directed to the utilization of polymyxin B (PMB) as a last-line treatment for life-threatening infections caused by multidrug resistant Gram-negative bacteria. Unfortunately, polymyxins resistance is also increasingly reported, leaving a serious threat to human health. Therefore, the establishment of rapid detection methods for PMB residues is highly essential to ensure public health. In this study, two monoclonal antibodies (mAb; 2A2 and 3C6) were obtained using PMB-bovine serum albumin as the immunogen and PMB-ovalbumin as the coating antigen, which were prepared with N-(γ-maleimidobutyryloxy) succinimide ester and glutaraldehyde as cross-linking agents, respectively. Through an indirect competitive enzyme-linked immunosorbent assay, resultant two mAbs were compared and the results indicated that 3C6 showed higher sensitivity with a half maximum inhibition concentration of 13.13 ng/mL. Based on 3C6, a gold nanoparticles (AuNPs)-based immunochromatographic test (ICT) strip was then established, the mechanism of which is that free PMB competes with the fixed coating antigen to combine with mAb labeled by AuNPs. Using ICT strip to detect milk and animal feed samples revealed the visible detection limits were 25 ng/mL and 500 μg/kg, respectively and the cutoff limits were 100 ng/mL and 1000 μg/kg, respectively. The ICT strip provides results within 15 min, facilitating rapid and semi-quantitative analysis of PMB residues in milk and animal feed.

Investigating nanohybrid material based on 3D CNTs@Cu nanoparticle composite and imprinted polymer for highly selective detection of chloramphenicol

Nanotechnology holds great promise for the fabrication of versatile materials that can be used as sensor platforms for the highly selective detection of analytes. In this research article we report a new nanohybrid material, where 3D imprinted nanostructures are constructed. First, copper nanoparticles are deposited on carbon nanotubes and then a hybrid structure is formed by coating molecularly imprinted polymer on 3D CNTs@Cu NPs; and a layer by layer assembly is achieved. SEM and AFM revealed the presence of Cu NPs (100-500nm) anchored along the whole length of CNTs, topped with imprinted layer. This material was applied to fabricate an electrochemical sensor to monitor a model veterinary drug, chloramphenicol. The high electron transfer ability and conductivity of the prepared material produced sensitive response, whereas, molecular imprinting produces selectivity towards drug detection. The sensor responses were found concentration dependent and the detection limit was calculated to be 10μM (S/N=3). Finally, we showed how changing the polymer composition, the extent of cross linking, and sensor layer thickness greatly affects the number of binding sites for the recognition of drug. This work paves the way to build variants of 3D imprinted materials for the detection of other kinds of biomolecules and antibiotics.

Lanthanide-Labeled Immunochromatographic Strip Assay for the On-Site Identification of Ancient Silk

The on-site identification of ancient silks has long been a key challenge in archeology. Therefore, a rapid, cost-effective, sensitive analytical approach is highly desirable. In this paper, a lanthanide-labeled immunochromatographic strip which is suitable for the on-site identification of ancient silks is described. Compared with the conventional colloidal gold-based immunochromatographic strip, this strip shows much higher analytical sensitivity and better quantitative discrimination. The limit of detection (LOD) of the strip for silk fibroin (SF) was calculated as 8.09 ng/mL, approximately 185 times lower than that of the colloidal gold-based immunochromatographic strip. No cross-reactions with other possible interfering antigens were observed. Moreover, the strip also shows good reproducibility, with a mean recovery of 94.15-102.55% and coefficient of variation of 5.22-17.57% in the repeated tests. Based on the advantages of portability and cost-effectiveness, as well as sensitivity, specificity, and reproducibility, the lanthanide-labeled immunochromatographic strip is a promising tool for on-site detection of ancient relics in archeological fieldwork.