Bead-based mesofluidic system for residue analysis of chloramphenicol

Recent progress of personal glucose meters integrated methods in food safety hazards detection

Development of personal glucose meters (PGMs) for blood glucose monitoring and management by the diabetic patients has been a long history since its first invention in 1968 and commercial application in 1975. The main reasons for its wide acceptance and popularity can be attributed mainly to the easy operation, test-to-result model, low cost, and small volume of sample required for blood glucose concentration test. During past decades, advances in analytical techniques have repurposed the use of PGMs into a general point-of-care testing platform for a variety of non-glucose targets, especially the food hazards. In this review, we summarized the recent published research using PGMs to detect the food safety hazards of mycotoxins, illegal additives, pathogen bacteria, and pesticide and veterinary drug residues detection with PGMs. The progress on PGM-based detection achieved in food safety have been carefully compared and analyzed. Furthermore, the current bottlenecks and challenges for practical applications of PGM for hazards detection in food safety have also been proposed.

Magnetic molecularly imprinted polymer prepared by microwave heating for confirmatory determination of chloramphenicol in chicken feed using high-performance liquid chromatography-tandem mass spectrometry

A magnetic molecularly imprinted polymer (MMIP) for chloramphenicol was prepared using a surface-imprinted and microwave-heating-induced polymerization method. The surfaces of the magnetic particles were first double-bond functionalized with 3-(trimethoxysilyl)propyl methacrylate (γ-MPS), followed by the copolymerization of 4-vinyl pyridine (4-VP) and trimethylolpropane trimethacrylate (TRIM) in the presence of chloramphenicol as a template and 1,1-azobis(cyclohexane-carbonitrile) (ABCN) as an initiator in a mixture of dimethyl sulfoxide and water with microwave heating at 80°C. The magnetic polymer possesses supraparamagnetic properties and was used to concentrate and cleanup chicken feed extract, followed by chromatographic separation using a Lichrospher®100 RP C8 column and detection with two multi-reaction monitoring transitions at m/z 321→ 152 and m/z 321→ 257. The mean recoveries obtained at two spiking levels were in the range of 94.6-100% The relative intra- and inter-day standard deviations were in the range of 1.4-2.6% and 5.1-5.7%, respectively. The detection limit of the method was 0.12 µg kg^-1. This confirmatory method was successfully applied to determine chloramphenicol in chicken feed samples.

Detoxification of the veterinary antibiotic chloramphenicol using electron beam irradiation

Electron beam irradiation has shown potential as an alternative process for the treatment of industrial effluents that contain toxic organic chemicals. This study investigated the effectiveness of electron beam in degrading chloramphenicol (CAP) in aqueous solution. The degradation efficiency was 32.4% at 1 kGy, 86.9% at 5 kGy, and 100% at 10 kGy. The total organic carbon (TOC) of CAP in aqueous solution declined 4.6% at 1 kGy, 12.1% at 5 kGy, and 17.1% at 10 kGy of irradiation with electron beam. The CAP degradation products after irradiation were CAP1 ([M + H] m/z 307.1), CAP2 ([M + H] m/z 291.1), and CAP3 ([M + H] m/z 321.1). The degradation products were tested for microbial toxicity against Escherichia coli, Pseudomonas putida, and Bacillus subtilis and did not show any toxic antimicrobial effects caused by the CAP degradation products after irradiation with electron beam. The results of this study suggest that electron beam irradiation is the best technology for the comprehensive treatment of veterinary antibiotics at wastewater treatment plants.

A cost-effective Z-folding controlled liquid handling microfluidic paper analysis device for pathogen detection via ATP quantification

A cost-effective microfluidic paper analysis device (μPAD) was developed with a special Z-folding design for controlling the fluidic flowing and substrate transportation. This presented μPAD can be easily fabricated through wax printing by using a solid ink printer which deposits wax onto the surface of a chromatographic paper, and then baked on a hotplate by penetrating the molten wax into the paper to create a hydrophobic barrier. After μPAD fabrication, liquid control and substrate transportation can be easily carried out by twice folding the μPAD following Z shape. The Z folding made two separated reagent holding zone connected while the detection reaction occurred with the connection. In this paper, a pathogens detection indicated by ATP quantification was took as a proof-in-principle application of using this presented μPAD, the limit of detection (LOD) was 1 μM for ATP detection and 2.6×10(7) CFU/mL for Salmonella live cell detection, which showed a great potential for Point-of-Care Testing (POCT) applications.

Advances of multiplex and high throughput biomolecular detection technologies based on encoding microparticles

The rapid developments of genomics and proteomics have driven the demand for multiplex and high throughput analysis of large numbers of biomolecules in the fields of medical diagnostics, drug discovery, and environmental monitoring. Encoding the biomolecular binding events is the key technique to fulfill this demand, in which microparticles play the most important roles. This review outlines the development of multiplex and high throughput biodetections, and highlights the most recent advances in the field of encoding microparticles, together with problems that need to be resolved.

Multiplexed bead-based mesofluidic system for detection of food-borne pathogenic bacteria

In the present study, a simple and rapid multiplexed bead-based mesofluidic system (BMS) was developed for simultaneous detection of food-borne pathogenic bacteria, including Staphylococcus aureus, Vibrio parahaemolyticus, Listeria monocytogenes, Salmonella, Enterobacter sakazakii, Shigella, Escherichia coli O157:H7, and Campylobacter jejuni. This system is based on utilization of isothiocyanate-modified microbeads that are 250 mum in diameter, which were immobilized with specific amino-modified oligonucleotide probes and placed in polydimethylsiloxane microchannels. PCR products from the pathogens studied were pumped into microchannels to hybridize with the oligonucleotide-modified beads, and hybridization signals were detected using a conventional microarray scanner. The short sequences of nucleic acids (21 bases) and PCR products characteristic of bacterial pathogens could be detected at concentrations of 1 pM and 10 nM, respectively. The detection procedure could be performed in less than 30 min with high sensitivity and specificity. The assay was simple and fast, and the limits of quantification were in the range from 500 to 6,000 CFU/ml for the bacterial species studied. The feasibility of identification of food-borne bacteria was investigated with samples contaminated with bacteria, including milk, egg, and meat samples. The results demonstrated that the BMS method can be used for effective detection of multiple pathogens in different foodstuffs.