A Fumonisins Immunosensor Based on Polyanilino-Carbon Nanotubes Doped with Palladium Telluride Quantum Dots (original) (raw)
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2015
An impedimetric immunosensor for fumonisins was developed based on poly(2,5-dimethoxyaniline)-multi-wall carbon nanotubes doped with palladium telluride quantum dots onto a glassy carbon surface. The composite was assembled by a layer-by-layer method to form a multilayer film of quantum dots (QDs) and poly(2,5-dimethoxyaniline)multi-wall carbon nanotubes (PDMA-MWCNT). Preparation of the electrochemical immunosensor for fumonisins involved drop-coating of fumonisins antibody onto the composite modified glassy carbon electrode. The electrochemical impedance spectroscopy response of the FB1 immunosensor (GCE/PT-PDMA-MWCNT/anti-Fms-BSA) gave a linear range of 7 to 49 ng L −1 and the corresponding sensitivity and detection limits were 0.0162 kΩ L ng −1 and 0.46 pg L −1 , respectively, hence the limit of detection of the GCE/PT-PDMA-MWCNT immunosensor for fumonisins in corn certified material was calculated to be 0.014 and 0.011 ppm for FB1, and FB2 and FB3, respectively. These results are lower than those obtained by ELISA, a provisional maximum tolerable daily intake (PMTDI) for fumonisins (the sum of FB1, FB2, and FB3) established by the Joint FAO/WHO expert committee on food additives and contaminants of 2 μg kg −1 and the
Materials, 2016
An impedimetric immunosensor for fumonisin B 1 (FB 1) was developed from a poly(2,5-dimethoxyaniline)-multi-walled carbon nanotube (PDMA-MWCNT) composite on the surface of glassy carbon electrode (GCE). The composite was prepared electrochemically and characterized using cyclic voltammetry. The preparation of the FB 1 immunosensor involved the drop-coating of a bovine serum albumin mixture of the anti-fumonisin antibody (anti-Fms) onto the composite polymer-modified GCE. The electrochemical impedance spectroscopy (EIS) responses of the FB 1 immunosensor (GCE/PDMA-MWCNT/anti-Fms) have a linear range of 7 to 49 ng¨L´1, and the corresponding sensitivity and detection limits are 0.272 kΩ L¨ng´1 and 3.8 pg¨L´1, respectively. The limit of detection of the immunosensor for certified corn sample (i.e., certified reference material) is 0.014 ppm FB 1 , which is in excellent agreement with the value published by the vendors and significantly more accurate than that obtained with enzyme-linked immunosorbent assay (ELISA).
Utilization of Synthetic Antibody for Fumonisin Determination in Feed and Food
Indonesian Bulletin of Animal and Veterinary Sciences, 2019
Fumonisin contamination in food is limited around 2 – 4 ppm and in feed for different animals varies from 5 to 100 ppm. This regulation is to prevent animal and human from carcinogenic effect from fumonisins. Measurement of fumonisins frequently uses chromatography methods such as High-Performance Liquid Chromatography (HPLC) and Liquid chromatography tandem-mass spectrometry (LCMS/MS); however, the sample preparation and analysis process for these methods are costly and time consuming. Immunoassays have also been employed for detecting fumonisins in food or feed. Unfortunately, the instability of antibody to harsh condition such as high temperature and pH becomes the drawback for immunoassay method. Currently, the technology based on molecularly imprinting, which is called synthetic antibody, has been established for replacing antibody functions. Therefore, the aim of this review is to describe development of molecularly imprinted polymer (MIP) in fumonisin analysis in feed and foo...
Fumonisins are one of the most agriculturally significant environmental toxins produced by Fusarium and Aspergillus species that grow on agricultural commodities in the field or during storage. Cereals contaminated with fumonisins causes serious loss to agricultural produce leads to health problems in humans and other farm animals. In the present study, polyclonal hyperimmune sera was raised against FB1 in rabbits immunized with FB1–keyhole limpet haemocyanin (KLH). Purified antibodies were used to establish a sensitive gold nanoparticle based immunochromatographic strip (ICG) for detecting FB1 levels in cereal grains. Effective on-site detection of FB1 was achieved by developing a rapid and sensitive pAb based ICG strip. This strip had a detection limit of 5 ng mL−1 for FB1 in cereal samples and it could be completed within 3 min. Close examination of 150 cereal samples by ICG strip method revealed that 77 were fumonisin-positive. Results obtained by the developed method was further validated with well standardized HPLC method and results of strip method was correlated well with those obtained by HPLC method. In conclusion, the developed method was a better alternative for onsite detection of FB1 in cereal samples intended for human consumption to reduce risk of humans and other farm animals. The high level of FB1 concentrations recorded in present study warrants the need to develop an awareness creation programme to the farmers of India for safe handling of cereal grains at the time of harvesting and storage of grains.
Development of an Electrochemical Immunosensor for Fumonisins Detection in Foods
2010
A simple sensor method was developed for aflatoxin M 1 analysis to be applied directly with milk by using antibody modified screen-printed carbon working electrode with carbon counter and silver-silver chloride pseudo-reference electrode. A competitive ELISA assay format was constructed on the surface of the working electrode using 3,3,5',5'-tetramethylbenzidine dihyrochloride (TMB) /H 2 O 2 electrochemical detection scheme with horseradish peroxidase (HRP) as the enzyme label. The performance of the assay and the sensor was optimised and characterised in pure buffer conditions before applying to milk samples. Extensive interference to the electroanalytical signal was observed upon the analysis of milk. Through a series of chemical fractionations of the milk, and testing the electrochemical properties of the fractions, the interference was attributed to whey proteins with focus towards lactalbumin. A simple pre-treatment technique of incorporating 18 mM calcium chloride, in the form of Dulbucco's PBS, in a 1:1 ratio to the milk sample or standards and also to the washing buffer stabilised the whey proteins in solution and eliminate the interfering signal. The resulting immunosensor was interference free and achieved a limit of detection of 39 ng l -1 with a linear dynamic detection range up to 1000 ng l -1 . The developed immunosensor method was compared to a commercial ELISA kit and an in-house HPLC method. The immunsensor was comparable, in term of sensitivity, but vastly superior in term of portability and cost therefore a key instrument for the detection of aflatoxin M 1 at the source of the contamination.
Analytica Chimica Acta, 2006
An enzyme-linked immunosorbent assay (ELISA) based on polyclonal antibody with enhanced chemiluminescent (ECL) detection of fumonisin B 1 (FB 1) in food samples has been developed. Assay conditions, including concentrations of antibody and enzyme conjugate, competition time and so on, were optimized. The effects of pH and two different organic solvents were investigated. The optimized ECL-ELISA system allowed FB 1 determination in a linear working range of 0.14-0.9 g L −1 with IC 50 value of 0.32 g L −1 and a limit of detection of 0.09 g L −1. The ECL-ELISA was about 10 times more sensitive and about 30% time less than that of colorimetric ELISA using the same antibody and HRP-conjugate. Good recoveries with spiked food samples were obtained, and the results correlated well with those obtained using conventional direct competition ELISA assay and HPLC method, which indicated that ECL-ELISA was capable of being applied for the specific detection and routine monitoring of FB 1 in food samples.
Journal of Agricultural and Food Chemistry, 2006
A rapid enzyme-linked immunosorbent assay (ELISA) test (microwell plate) and a membrane-based colloidal gold immunoassay in flow-through and lateral-flow formats for the rapid detection of fumonisin B 1 (FB 1) were developed. The rapid microwell assay can be completed within 20 min with the detection limit of 0.5 (0.2 µg/L. Membrane-based colloidal gold immunoassays had a visual detection limit of 1.0 µg/L for FB 1 with the detection time of <10 min. Matrix interference was eliminated by 15-fold dilutions of methanol extracts with buffer. These immunoassays can be used as quantitative or qualitative tools for the rapid detection of FB 1 residues in 10-20 min on-site.
Journal of Chromatography A, 2008
A sensitive and selective analytical method was developed for the quantitative determination of fumonisins B 1 and B 2 in maize-based foods for direct human consumption. The method, based on highperformance liquid chromatography and fluorescence detection, presents a rapid and automated on-line post-column derivatization, performed with o-phtalaldehyde and N,N-dimethyl-2-mercaptoethylamine. Several factors affecting the separation and detection of fumonisins were investigated, including mobile phase composition, column features, derivatization agent flow-rate and both the excitation and the emission wavelengths. Optimal fluorescence detection was obtained by using a exc of 343 nm and a em of 445 nm. Under the optimized experimental conditions, a complete separation of fumonisins was obtained in less than 13 min by using a C 18 column and a gradient elution at 0.8 mL/min with methanol and 0.1 M phosphate buffer at pH 3.15. The limits of detection for FB 1 and FB 2 were 4 and 5 g/L corresponding to 5 and 6 g/kg in matrix. Each fumonisin was determined in the range 40-320 g/L that correspond to 50-400 g/kg in matrix. The necessary requirements for accuracy, reproducibility and sensitivity were fulfilled and recovery values ranged from 87 to 94% for FB 1 and from 70 to 75% for FB 2 in cornflake samples at three fortification levels in the range 100-300 g/kg. The potential of this method, combined with a simple clean-up procedure, was assessed by the measurements of FB 1 and FB 2 in maize-based products, such as maize flour, "polenta", tortillas and cookies.
Food Additives and Contaminants, 2001
The determination of fumonisins in cornXakes is a challengin g matter as the actually available methods for the analysis of corn do not perform well when applied to this more complex matrix. After testing several factors that may aVect the analytical performance, an accurate method for the determination of fumonisin B 1 (FB 1 ) and B 2 (FB 2 ) in cornXakes has been developed. The method uses immunoaYnity chromatography for clean-up and high performance liquid chromatograph y (HPLC) for quantiWcation of the toxins. Samples were extracted twice with acetoni-trile± methanol± water (25:25:50) and the combined extracts were diluted with phosphate buVered saline (PBS) and applied to a FumoniTest TM immunoaYnity column. After washing with PBS, fumonisins were eluted from the column with methanol and reacted with o-phthaldialdehyde /2-mercaptoethanol to form Xuorescent derivatives. Fumonisin derivatives were analysed by reversed phase HPLC with Xuorometric detection using methanol± 0.1 M phosphat e buVer (77:23; pH adjusted at 3.35) as mobile phase. The average recoveries for FB 1 and FB 2 spiked in the ranges of 0.33± 2.80 ·g/g and 0.17± 1.40 ·g/g were 102.6% and 95.1% , respectively, with average relative standard deviations of 9% and 8% . The limit of quantiWcation for FB 1 and FB 2 was 0.005 ·g/g based on a signal-to-noise ratio of 6:1 by using a sensitive Xuorescence detector. The method was used to analyse 18 cornXakes and cornXake cereals samples for FB 1 and FB 2 contamination. All but one sample were found to be contaminated, with maxi-mum FB 1 and FB 2 concentrations of 1.092 ·g/g and 0.235 ·g/g, respectively. Mean FB 1 and FB 2 concentrations were 0.157 ·g/g and 0.036 ·g/g, respectively.