Article

Simultaneous and rapid detection of six different mycotoxins using an immunochip.

College of Food Science and Technology, Huazhong Agricultural University, Wuhan, PR China.
Biosensors & bioelectronics (Impact Factor: 5.43). 01/2012; 34(1):44-50. DOI: 10.1016/j.bios.2011.12.057
Source: PubMed

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.

0 Bookmarks
 · 
86 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: A technique for multiplex detection of organophosphorus pesticides and carbamate pesticides has been developed using a suspension array based on silica-hydrogel hybrid microbeads (SHHMs). The main advantage of SHHMs, which consist of both silica and hydrogel materials, is that they not only could be distinguished by their characteristic reflection peak originating from the stop-band of the photonic crystal but also have low non-specific adsorption of proteins. Using fluorescent immunoassay, the LODs for fenitrothion, chlorpyrifos-methyl, fenthion, carbaryl and metolcarb were measured to be 0.02ng/mL, 0.012ng/mL, 0.04ng/mL, 0.05ng/mL and 0.1ng/mL, respectively, all of which are much lower than the maximum residue limits, as reported in the European Union pesticides database. All the determination coefficients for these five pesticides were greater than 0.99, demonstrating excellent correlations. The suspension array was specific and had no significant cross-reactivity with other chemicals. The results for the detection of pesticide residues collected from agricultural samples using this method agree well with those from liquid chromatography-tandem mass spectrometry. Our results showed that this simple method is suitable for simultaneous detection of these five pesticides residues in fruits and vegetables.
    Journal of hazardous materials 03/2014; 273C:287-292. · 4.14 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The present study describes the development, optimization and performance comparison of three ELISAs and one multiplex immunoassay in a microarray format. The developed systems were dedicated to the detection of three different classes of pollutants (pesticide, explosive and toxin) in water. The characteristics and performances of these two types of assays were evaluated and compared, in order to verify that multiplex immunoassays can replace ELISA for multiple analyte sensing. 2,4-Dichlorophenoxyacetic acid, 2,4,6-trinitrotoluene and okadaic acid were chosen as model targets and were immobilized in classical microtiter plate wells or arrayed at the surface of a microarray integrated within a classical 96-well plate. Once optimized, the classical ELISAs and microarray-based ELISA performances were evaluated and compared in terms of limit of detection, IC50, linearity range and reproducibility. Classical ELISAs provided quite good sensitivity (limit of detection down to 10 μg L(-1)), but the multiplex immunoassay was proven to be more sensitive (limit of detection down to 0.01 μg L(-1)), more reproducible and an advantageous tool in terms of cost and time expenses. This multiplex tool was then used for the successful detection of the three target molecules in spiked water samples and achieved very promising recovery rates.
    Environmental science. Processes & impacts. 08/2013;
  • [Show abstract] [Hide abstract]
    ABSTRACT: A novel multiplex chemiluminescent mycotoxin immunoassay suspension array system was developed by combining the silica photonic crystal microspheres (SPCMs) encoding technique and a chemiluminescent immunoassay (CLIA) method. The SPCMs were used as a carrier of the suspension array and encoded by their reflectance peak positions, which overcome fluorescence photobleaching, and the potential interference between the encoding fluorescence and detection fluorescence. Aflatoxin B1 (AFB1), fumonisin B1 (FB1) and ochratoxin A (OTA) artificial antigens were immobilized on the surfaces of SPCMs by using 3-glycidoxypropyltrimethoxysilane as a linker. Horseradish peroxidase (HRP) was used as a labeling enzyme for the secondary antibody in the enzyme-catalyze H2O2-luminol chemiluminescence system. The CLIA detection system was easily integrated with a multifunctional microplate reader and displayed a two to three orders of magnitude dynamic linear detection range from 0.001 to 1, 0.001 to 1, and 0.01 to 1 ng mL(-1) for AFB1, FB1 and OTA with 50% inhibitory concentrations (IC50) of 0.01, 0.036, and 0.04 ng mL(-1), respectively. The recovery rates are in the range of 63.5 to 121.6% for the three mycotoxins in three kinds of spiked cereal samples. The results of detection in 12 naturally contaminated cereal samples were consistent with that of the classic enzyme-linked immunosorbent assay (ELISA) method. This proposed system is simple, rapid, low cost and high throughput for multiplex mycotoxin assay.
    The Analyst 12/2013; · 4.23 Impact Factor