Participating Young Investigators: Dr. Chrysoula-Evangelia Karachaliou & Dr. George Koukouvinos

Academic Advisor: Dr. Evangelia Livaniou

Vice Academic Advisor: Dr. Sotirios Kakabakos

Budget: 50,050 euros

One of the most important groups of pesticides is composed of low molecular weight – organic molecules (“haptens”) bearing a benzimidazole-core in their structure (benzimidazole-type pesticides, e.g., carbendazim, benomyl), which act especially as fungicides. Despite the unequivocal advantages they have offered to agriculture, benzimidazole-type pesticides have been associated with a series of toxic effects that they may cause to living organisms, usually through the food chain. For this reason, regular assessment of their levels in specific samples is necessary, which is usually achieved by means of instrumental analysis. Alternatively, immunochemical assays have been developed for the aforementioned pesticides; however, application of these assays is rather limited, since the necessary primary antibodies have been produced (and exclusively used) by a few research teams, against very specific, in-house prepared synthetic haptens, and are not, therefore, commercially/widely available.

In the frame of this project, immunochemical methodology including an ELISA and a white light reflectance spectroscopy based – biosensor (WLRS-biosensor assay) will be developed for determining a series of benzimidazole-type pesticides in complex samples, such as food commodities (e.g., fruit juices), in a reliable, fast, easy and cost-effective way. The analytical methodology proposed will be based on suitable polyclonal antibodies, which will be produced in our labs against a combination of benzimidazole derivatives, each bearing a different active chemical group (i.e., against a “cocktail” of immunizing haptens), following a protocol we have previously published (Zikos et al., 2015). Synthetic poly-lysine dendrimers ending at suitable benzimidazole-derivatives will be tested as immobilizing agents and their ability to effectively coat the ELISA microwells or the biosensor – sensing surface will be evaluated, too. Efforts will be made toward minimization of the “matrix effect” that various complex samples (e.g., fruit juices) may cause on the assay analytical characteristics as well as toward achievement of analytical detection limits lower than the maximum residue levels (MRL) set by National and European legislation for these pesticides.

The new analytical methodology is expected to contribute to solving persistent problems that are associated with hapten immunoassays, while it will allow determination of a series of benzimidazole-type pesticides, due to the primary polyclonal antibodies that will be developed against a combination of different benzimidazole-derivatives. Moreover, this methodology is expected to be suitable for the analysis of a great number of samples by employing enzyme-labels (ELISA assay) as well for label-free and eventually on-site application (WLRS biosensor-assay). In conclusion, the new analytical methodology is expected to serve as a feasible and reliable tool, which might be exploited in broad repertoire of research studies.

Zikos C, Evangelou A, Karachaliou C-E, Gourma G, Blouchos P, Moschopoulou G, Yialouris C, Griffiths J, Johnson G, Petrou P, Kakabakos S, Kintzios S, Livaniou E. Commercially available chemicals as immunizing haptens for the development of a polyclonal antibody recognizing carbendazim and other benzimidazole-type fungicides. Chemosphere, 119, S16-S20 (2015) DOI: 10.1016/j.chemosphere.2014.03.049