Peculiarities of sample preparation for the determination of certain mycotoxins in grain products and fruits by immunobiosensor analysis
Our current report focuses on effective ways of sample preparation for detection of mycotoxins aflatoxin B1 and T2 in grain products (wheat, maize, sunflower and oats) as well as patulin in fruits (plum, apple and grape) by the surface plasmon resonance (SPR) immunobiosensor. An effective method for carrying out analysis of mycotoxins by an SPR Immunobiosensor was assessed, and the results obtained were compared with those determined in a traditional ELISA method. The analysis with the immunobiosensor is capable to be carried out in a direct format on the basis of mycotoxin-specific antibodies immobilized on the sensor surface, but its sensitivity was found to be lower than that obtained in a competitive format on the basis of an immobilized mycotoxin conjugate. Due to this characteristic difference in analytical sensitivity, we recommend the former format for screening for the presence of mycotoxins in environmental samples. In turn, the latter format is proposed for verification of the obtained results of analysis. The competitive analysis by the immunobiosensor has demonstrated sensitivity in the range of the traditional ELISA method. Organic solvent extraction of the three mycotoxins, aflatoxin B1, T2 and patulin from produce samples was carried out with acetonitrile and methanol, and the former solvent was concluded that preferable. Particular attention was paid to the problem of matrix components detrimentally affecting extractability and the immunochemical reaction: difficulties due to the presence of small quantities of vegetable oil in grain products needed to be overcome. In cases of samples of substantial vegetable oil content, acetone as an extraction solvent is recommended, the use of which did not appear to affect immunoanalysis results. It was demonstrated that the analysis of patulin in fruits depends on pH of the obtained samples, especially if mycotoxin content is determined in an unripe stage. In such cases, pH determination and neutralization by a special buffer prior to immunoanalytical measurements are recommended.
Surface plasmon resonance, immunobiosensor, ELISA, mycotoxins, sample preparation, article
Peculiarities of sample preparation for the determination of certain mycotoxins in grain products and fruits by immunobiosensor analysis / N. F. Starodub, M. V. Savchuk, A. Székács, J. L. Marty // World Journal of Engineering Research and Technology. - 2018. - Vol. 4, Issue 3. - P. 174-185.