Development of an electrochemical immunosensor for aflatoxin M1 in milk with focus on matrix interference

Parker, Charlie O; Tothill, Ibtisam E.

doi:10.1016/j.bios.2008.12.021

Cited by 91 publications

(55 citation statements)

References 41 publications

(39 reference statements)

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“…8,14,15 However, the quantitative approaches require complicated pretreatment, professional operators and expensive instruments. Some immunological methods like enzyme-linked immune sorbent assay (ELISA) [16][17][18] and immunosensors [19][20][21] have also been reported for AFM 1 detection. There are disadvantages in both preparation of the antibody and its stability and this limits its application in the field.…”

Section: Introductionmentioning

confidence: 99%

A qPCR aptasensor for sensitive detection of aflatoxin M1

et al. 2016

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. In addition, the aptasensor developed here exhibits high selectivity for AFM 1 over other mycotoxins and small effects from cross-reaction with structural analogs. The method proposed here has been successfully applied to quantitative determination of AFM 1 in infant rice cereal and infant milk powder samples. Results demonstrated that the current approach is potentially useful for food safety analysis, and it could be extended to a large number of targets. IntroductionAflatoxin M 1 (AFM 1 ), one of the most toxic contaminants in dairy products, is a metabolite produced by dairy cows as a result of being fed with feeds contaminated with Aflatoxin B 1 (AFB 1 ). [3][4][5] Once present in dairy products, AFM 1 poses a hazard to humans (especially infants) who consume them. Results and Discussion Optimization of the amplification of complementary ssDNAThe complementary ssDNA is applied as the subsequent PCR template. The Optimization of streptavidin and the biotinylated aptamerOther factors would affect the performance of this method including the concentrations of streptavidin, the biotinylated aptamer and the complementary ssDNA and these all should be optimized. Under a fixed concentration of complementary ssDNA at 10 nM, the concentrations of streptavidin and the 6 biotinylated aptamer were analyzed for the PCR amplification signal change (Fig. S3).The adsorptive power of streptavidin to PCR tubes and the binding ability of streptavidin-coated tubes to biotinylated aptamer was primarily detected using different concentrations of streptavidin (Fig. S3). This also shows that there was a clear difference of Ct values between the control group and streptavidin-coated tubes, which showed the intense adsorptive ability between biotinylated aptamer and streptavidin-coated tubes. In analysis of the Ct values at different concentrations of streptavidin, the Ct value reached the lowest level when the concentration of streptavidin was 2.5 ng mL -1 . This graph also shows that the Ct values decreased with the increase of the amount of aptamer when aptamer levels were below 10.0 nM andalso that the Ct values increased with the amount of aptamer above 10.0 nM mainly because of steric hindrance. Thus, 2.5 ng mL -1 of streptavidin and 10 nM of aptamer were the optimal conditions for RT-qPCR amplification. AFM 1 determinationUnder optimal conditions, the amplification curves and calibration curve of this aptasensor for different levels of AFM 1 with AFM 1 DNA1 were determined by RT-qPCR (Fig. 1). As is shown in Fig. 1(A), the cycle number increased with an increase in AFM 1 . More complementary ssDNA would be released when more AFM 1 is present in the reaction system, which leads to a decrease in the amount of the PCR template and an increase in cycle number. Meanwhile, a good linear relationshipbetween Ct values and AFM 1 levels in the range of 1×10 -4 to 1 µg L -1 was obtained as (Table 1). Specificity analysisThe specificity of the aptasensor plays an important role in the development and practicality of this method. In ...

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Section: Introductionmentioning

confidence: 99%

A qPCR aptasensor for sensitive detection of aflatoxin M1

et al. 2016

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“…By utilizing the above detailed measuring parameters, the improved OWLS-based method is about one order of magnitude more sensitive than those obtained with similar competitive immunosensors using electrochemical detection (BADEA et al, 2004;MICHELI et al, 2005;PARKER & TOTHILL, 2009).…”

Section: Afm1 Determination In Milk Samplesmentioning

confidence: 99%

“…Most of the reported AFM1 sensors are immunosensors, as the best selectivity can be achieved by using specifi c antibodies against the target molecule. For this reason, many immunosensors (BADEA et al, 2004;MICHELI et al, 2005;PARKER & TOTHILL, 2009) have been developed in the last decade. Although these methods showed good selectivity, each of them required enzyme-labelling and electrochemical detection.…”

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confidence: 99%

Determination of aflatoxin M1 in milk samples by an OWLS-based immunosensor

Szalontai¹,

Kiss²,

Adányi³

2014

Acta Alimentaria

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An immunoreaction-based method was investigated for the detection of afl atoxin M1 (AFM1), which is the hydroxylated metabolite of afl atoxin B1 (AFB1). This mycotoxin may be found in milk and milk products obtained from livestock that have ingested contaminated feed. Quantitative analysis of AFM1 was carried out using indirect (competitive) immunoassay method, which can be used for low weight molecules. The real-time measurement was done with Optical Waveguide Lightmode Spectroscopy (OWLS) technique. After the optimization of the chemical and biochemical parameters (determination of the optimal concentration of the immobilized AFM1-protein conjugate, determination of the AFM1 antibody content of the samples, etc.) real samples were also examined. Three kinds of milk sample preparation methods (fi ltration, centrifugation, size exclusion centrifugation) and two dilution rates (100 and 200 fold) were compared. The presented competitive immunoassay method showed the best results when 100 fold diluted fi ltered or centrifuged milk samples were examined. The dynamic measuring ranges for AFM1 were 0.001-0.1 ng ml -1 and 0.0005-0.01 ng ml -1 , respectively.

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“…Obtained results showed that, using SPEs, AFM1 can be measured up to 25 pg/mL with a dynamic working range between 30 and 160 pg/mL. Meanwhile, in a study by Parker et al, it was concluded that the presence of divalent ion (calcium) is highly recommended to stabilize the milk samples on metal electrodes [51]. For multi-analyte determinations, a competitive ELISA combined with 96-well screen-printed microplate-based multichannel electrochemical detection was developed for AFB1 detection in corn samples using intermittent pulse amperometry (IPA) [52].…”

Section: Electrochemical Immunosensors For Afs Detectionsmentioning

confidence: 99%

Recent Advances in Electrochemical-Based Sensing Platforms for Aflatoxins Detection

et al. 2016

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Abstract:Mycotoxin are small (MW~700 Da), toxic secondary metabolites produced by fungal species that readily colonize crops and contaminate them at both pre-and post-harvesting. Among all, aflatoxins (AFs) are mycotoxins of major significance due to their presence in common food commodities and the potential threat to human health worldwide. Based on the severity of illness and increased incidences of AFs poisoning, a broad range of conventional and analytical detection techniques that could be useful and practical have already been reported. However, due to the variety of structural analogous of these toxins, it is impossible to use one common technique for their analysis. Numerous recent research efforts have been directed to explore alternative detection technologies. Recently, immunosensors and aptasensors have gained promising potential in the area of sample preparation and detection systems. These sensors offer the advantages of disposability, portability, miniaturization, and on-site analysis. In a typical design of an aptasensor, an aptamer (ssDNA or RNA) is used as a bio-recognition element either integrated within or in intimate association with the transducer surface. This review paper is focused on the recent advances in electrochemical immunoand aptasensing platforms for detection of AFs in real samples.

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Development of an electrochemical immunosensor for aflatoxin M1 in milk with focus on matrix interference

Cited by 91 publications

References 41 publications

A qPCR aptasensor for sensitive detection of aflatoxin M1

A qPCR aptasensor for sensitive detection of aflatoxin M1

Determination of aflatoxin M1 in milk samples by an OWLS-based immunosensor

Recent Advances in Electrochemical-Based Sensing Platforms for Aflatoxins Detection

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