DNA directed immobilization (DDI) for the development of an antibody fluorescent microarray for the determination of three family antibiotic residues in milk.

Abstract

Misuse of antibiotics in food producing animals enhances the possibility to develop antibiotic resistance and can also lead to the appearance of these compounds in derivate products. New strategies to overcome this issue are required. In this context, the FoodSmartphone project will provide analytical tools to ensure food quality concerning pesticides, veterinary products or allergens, from farm to fork. The first approach is based on fluorescent microarrays which emerge as potential screening tools to determine the presence of multiple analytes at the same time. In this study, we present a multiplexed analytical platform based on hapten-oligonucleotide arrays to detect three families of antibiotics. The use of hapten-oligonucleotide conjugates allows the directed immobilization (DDI) of the signal for each antibiotic family by immobilizing the complementary oligo-probes over the surface of glass slide. After hybridization, the cocktail of primary antibodies is added in the samples and this binding is elucidated by the addition of secondary antibodies labeled to a fluorophore which provide the fluorescent signal. Using this system a group of penicillin, sulfonamides and tylosin can be quantified on buffer and milk samples. The format of this assay will provide the basis for its implementation on a Smartphone readout system