Development and optimization of Electrochemical Affinity Biosensors for the control of food safety

The guarantee of food safety requires a fast and accurate control for all chemicals and bacteria, which are harmful for human health. In the food industry, the safety of a product is evaluated through periodic chemical and microbiological analysis; these procedures use techniques as chromatography, spectrophotometry, and electrophoresis that are expensive, time consuming, require highly trained personnel and require steps of sample pretreatment, increasing the time of analysis. Therefore, the demand for developing simple, rapid, accurate, low-cost and portable analytical instruments is growing and detection of chemical and microbiological contaminants (mycotoxins, pathogenic microorganisms, pesticides and allergens) that endanger the food safety. Biosensors, analytical devices composed of a biological recognition element (such as enzyme, antibody, receptor) coupled to a chemical or physical transducer (electrochemical, mass, optical), offer a possible alternative to common approaches, by allowing rapid on site analysis, and providing real-time information during the food production process. Biosensor literature in the field of food safety is focused mainly on affinity biosensors, which are considered as a further subset of biosensors that use an antibody, sequence of DNA or protein interfaced to a signal transducer to measure a binding event; most of them are based on the very high-affinity interaction between antigen and specific antibodies, but novel specific ligands (e.g. aptamers) are emerging. However, the affinity biosensors described in literature belong to the “labelled affinity biosensors” which require the use of labels (commonly enzymes), linked to the target biomolecule, able to detect the immune-complex thanks to the production of substances easily detected by electrochemical or optical transducer systems. The drawback of immunosensors labelled is due to extra costs and time for labelling step and the impossibility of real time detection... [edited by Author]