Abstract

The use of antibiotics is a common practice on dairy farms in the treatment of mastitis and other diseases. However, intensive use of these drugs and improper handling can lead to contamination of raw milk, with consequent impacts on food safety and the health of the population. These impacts include allergies and other toxic effects, and induction of bacterial multi-resistance to antibiotics, which is an international problem with serious consequences for public health. Screening kits available for rapid detection of antibiotic residues in raw milk, such as Delvotest® and other rapid methods (eg. SNAP® tests) have disadvantages, such as lack of quantitative result, lack of specificity and automation by requiring stages of sample and device handling. Therefore, the opportunity that arises from this line of applied research is the development of a opto-electronics sensor based on a biological transducer (optoelectronic biosensor), which combine speed and portability (screening methods) with quantitative analytical capability (typical of instrumental methods) and high specificity for the following antibiotics often used in dairies: ampicillin (b-lactam), oxytetracycline (tetracycline), sulfadimetoxine (sulfonamide) and kanamycin (aminoglycoside). The optical and analytical phenomena to characterize in this research is the bio-recognition of antibiotics, which is based on a system of gold nanoparticles functionalized with aptamers (oligonucleotides) specific for each antibiotics (corresponds to the biosensor). Antibiotics recognition induces aggregation of nanoparticles and color change (optical signal) as a result of surface plasmon excitation, whose detection in raw milk will be studied by radiometric technology and detection algorithm noise signal.