Simultaneous and rapid detection of six different mycotoxins using an immunochip.
ABSTRACT Mycotoxins are highly toxic contaminants in food, animal feed, and commodities. The study has developed an immunochip for quantifying the concentrations of six mycotoxins: aflatoxin B1, aflatoxin M1, deoxynivalenol, ochratoxin A, T-2 toxin, and zearalenone, which were added to drinking water. The complete antigens (Ags) of the mycotoxins were contact printed and immobilized onto agarose-modified glass slides with 12 physically isolated subarrays, based on the reaction of both diffusion and covalent bond. The optimal concentration of each antigen and antibody (Ab) was obtained using an Ag-Ab immunoassay. Based on the indirect competitive immunoassay for the simultaneous detection of six mycotoxins in one single chip, six standard curves with good logistic correlation (R(2)>0.97) were respectively plotted. The working ranges (0.04-1.69, 0.45-3.90, 20.20-69.23, 35.68-363.18, 0.11-1.81, and 0.08-7.47 ng/mL, respectively) were calculated, as well as the median inhibitory concentrations (0.31±0.04, 1.49±0.21, 34.54±1.30, 134.06±11.75, 0.49±0.05, and 1.54±0.22 ng/mL, respectively), when six mycotoxins were detected simultaneously. Finally, the recovery rates in drinking water generally ranged from 80% to 120% on the same chip, with an intra-assay coefficient of variation lower than 15%. We successfully established an immunochip for simultaneous detection of six mycotoxins within 4h, with advantages of using minimal samples and being visually semiquantitative with our naked eyes. In summary, the method could be developed on one single chip for detecting multiple contaminants in actual samples.
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ABSTRACT: The aim of this manuscript was the development of easy-to-operate quantum dots (QDs)-based immunochemical techniques for simultaneous screening of several mycotoxins in cereals. Two different approaches for multiplex fluorescent immunosorbent assay (FLISA) were employed. In the first approach a multiwell plate in which the different wells express a different mycotoxin (deoxynivalenol, zearalenone, aflatoxin B1, T2-toxin and fumonisin B1) was considered as a multiplex because each sample was pretreated once and then will be distributed over a series of wells within the same plate (single-analyte multiplex, SAM). The entire assay allows the simultaneous determination of all compounds. For the double-analyte multiplex (DAM) two different specific antibodies were co-immobilized in one single well. Zearalenone and aflatoxin B1 were simultaneously determined, provided their conjugates are labeled with QDs which are fluorescent in different parts of the spectrum, by scanning the assay outcome at two different wavelengths. The limits of detection (LOD) for the simultaneous determination of deoxynivalenol, zearalenone, aflatoxin B1, T2-toxin and fumonisin B1 by SAM FLISA were 3.2, 0.6, 0.2, 10 and 0.4 µg kg−1, respectively, while for the DAM FLISA they were 1.8 and 1 µg kg−1 for zearalenone and aflatoxin B1, respectively. SAM FLISA principle was also presented in a qualitative on-site format and tested for on-site multiplex determination of four mycotoxins in cereals. The achieved cut-off values of 500, 100, 2 and 100 µg kg−1 for deoxynivalenol, zearalenone, aflatoxin B1 and T2-toxin respectively. For simplification of multiassay results' evaluation the conjugates with QDs of different colors were used.Biosensors & Bioelectronics 12/2014; 62:59-65. · 6.45 Impact Factor
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ABSTRACT: Detection of multiple toxic mycotoxins is of importance in food quality control. Surface plasmon resonance imaging (SPRi) is an advanced tool for simultaneously multiple detections with accuracy; however, it suffers from limited sensitivity due to the instrumental constraint and small sizes of mycotoxins with only one epitope for an insensitive competitive immunoassay. In this work a gold nanoparticle (AuNP)-enhanced SPRi chip is designed to sensitively detect multiple mycotoxins using a competitive immunoassay format. The sensing surface is constructed by uniformly attaching dense mycotoxin antigens on poly[oligo(ethylene glycol) methacrylate-co-glycidyl methacrylate] (POEGMA-co-GMA) brush modified SPRi gold chip. After competitive binding in a sample solution containing respective monoclonal antibodies, secondary antibody-conjugated AuNPs are employed to bind with the captured monoclonal antibodies for further amplification of the SPRi signal. Highly specific and sensitive simultaneous detection is achieved for three typical mycotoxins including Aflatoxin B1 (AFB1), Ochratoxin A (OTA) and Zearalenone (ZEN) with low detection limits of 8, 30 and 15pgmL(-1) and dynamic ranges covering three orders of magnitude.Journal of Colloid and Interface Science 06/2014; 431C:71-76. · 3.55 Impact Factor
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ABSTRACT: The safety of traditional Chinese medicine (TCM) is a major strategic issue that involves human health. With the continuous improvement in disease prevention and treatment, the export of TCM and its related products has increased dramatically in China. However, the frequent safety issues of Chinese medicine have become the ‘bottleneck’ impeding the modernization of TCM. It was proved that mycotoxins seriously affect TCM safety; the pesticide residues of TCM are a key problem in TCM international trade; adulterants have also been detected, which is related to market circulation. These three factors have greatly affected TCM safety. In this study, fast, highly effective, economically-feasible and accurate detection methods concerning TCM safety issues were reviewed, especially on the authenticity, mycotoxins and pesticide residues of medicinal materials.Acta Pharmaceutica Sinica B. 01/2015;