Current methodologies for detection of food contamination based on heavy analytical tools cannot guarantee a safe and stable food supply. The reasons are the complexity, the long time-to-result (2-3 days) and the cost of these tools, which limit the number of samples that can be practically analyzed at food processing and storage sites. The need for screening tools that will be still reliable but simple, fast, low-cost, sensitive and portable for in-situ application is thus urgent. BIOFOS aims to address this need through a high-added value, reusable biosensor system based on optical interference and lab-on-a-chip (LoC) technology.To do this, BIOFOS will combine the most promising concepts from the photonic, biological, nanochemical and fluidic parts of LoC systems, aiming to overcome limitations related to sensitivity, specificity, reliability, compactness and cost issues. BIOFOS will rely on the ultra-low loss TriPleX photonic platform in order to integrate on a 4x5 mm2 chip 8 micro-ring resonators, a VCSEL and 16 Si photodiodes, and achieve a record detection limit in the change of the refractive index of 5•10-8 RIU. To support reusability and high specificity, it will rely on aptamers as biotransducers, targeting at chips for 30 uses. Advanced surface functionalization techniques will be used for the immobilization of aptamers, and new microfluidic structures will be introduced for the sample pre-treatment and the regeneration process. BIOFOS will assemble the parts in a 5x10x10 cm3 package for a sample-in-result-out, multi-analyte biosensor. The system will be validated in real settings against antibiotics, mycotoxins, pesticides and copper in milk, olive oil and nuts, aiming at detection below the legislation limits and time-to-result only 5 minutes. Based on the reusability concept, BIOFOS also aims at reducing the cost per analysis by at least a factor of 10 in the short- and 30 in the mid-term, paving the way for the commercial success of the technology.