Applied Nanophotonics, Liquid Crystals and Biomedical Optics

Background: Food safety is becoming increasingly important because food industry must provide quality products to minimize the health risks. Traditional methods to assure food safety, such as plate count and polymerase chain reaction are accurate and robust but can hardly satisfy the needs of the food industry because they are costly and time consuming. Therefore, optical biosensors that can analyze food in a low-cost, facile, fast, sensitive, and selective manner started to emerge. Scope and approach: This review presents plasmonic biosensors including surface plasmon resonance (SPR), localized SPR (LSPR), fiber optic SPR (FO-SPR), surface enhanced Raman scattering (SERS), surface-enhanced fluorescence (SEF), and total internal reflection (TIR) based sensors and their applications in food pathogens monitoring. Moreover, the strengths and weaknesses of plasmonic biosensors implementation in food control are showcased. Key findings and conclusions: Plasmonic biosensors could simplify procedure and radically reduce time, price and consummation of reactants, compared to traditional microbiological methods. Optical biosensors, in particular SPR, have been developed for detection of different foodborne pathogens. In parallel, analytical improvements have been achieved by coupling different techniques (fiber optics, Raman, fluorescence, luminescence) to plasmonic sensors in order to reduce the limits of detection and to improve sensitivity. The future improvements include the miniaturization of instruments to handheld devices and simplification of analysis to enable direct target detection in food matrices. Plasmonic technology can certainly have long lasting impact because the need for a simple and rapid food assay is pressing and guarantees the future development in this field.