Optical Bioprobe for Detection of Veterinary Antibiotic Residues in Milk Samples

The challenge of food safety requires the employment of field analytical tools based on rapid and effective methods for early identification of chemical-toxicological hazards. Biosensoristic devices possess suitable characteristics in terms of analytical performance, easy use, capacity of providing real-time results, minimised use of reagents and cost-effectiveness. In particular, my current research activity focuses on whole cell bioprobes and the design and development of a optical fluorescent bioprobe based on transgenic microbial cells for the detection of fluoroquinolones in milk samples. The uncontrolled use of veterinary antibiotics in dairy animals poses the problem of residues in milk: when residues exceed the maximum residue limits (MRLs), milk is unfit for consumption. Therefore the progresses in genetic engineering allow the modification of unicellular microorganisms into inducible bioreporters usable as efficient biomediators for semi or quantitative optical analyses (e.g. fluoroquinolones) through a biosensoristic device. Using a specific DNA construct (inducible promoter fused to a reporter gene e.g. GFP gene), genetically engineered E. coli B strain ATCC 11303 cells will be coupled with a suitable transduction element. Parameters likely to influence the analytical detection will be tested and optimized as well as the proper type of immobilization (if necessary). The possibility of designing disposable or reusable biomediators will be also considered. This research is carried out as part of the technology platform ALERT - Integrated System of biosensors and sensors (BEST) for monitoring the health, the quality and traceability of bovine milk - (www.alert2015.it).