Optical fiber extrinsic Fabry-Perot interferometric (EFPI)-based biosensors

A novel system incorporating optical fiber extrinsic Fabry-Perot interfermometric (EFPI)-based sensors for rapid detection of biological targets is presented. With the appropriate configuration, the EFPI sensor is able to measure key environmental parameters by monitoring the interferometric fringes resulting from an optical path difference of reflected signals. The optical fiber EFPI sensor has been demonstrated for strain, pressure, and temperature measurements and can be readily modified for refractive index measurements by allowing solutions to flow into an open cavity. The sensor allows for highly sensitive, real-time, refractive index measurements and by applying affinity coatings containing ligands within this cavity, specific binding of target molecules can be accomplished. As target molecules bind to the coating, there is an increased density within the film, causing a measurable refractive index change that correlates to the concentration of detected target molecules. This sensor platform offers enhanced sensing capabilities for clinical diagnostics, pharmaceutical screening, environmental monitoring, food pathogen detection, biological warfare agent detection, and industrial bioprocessing. Promising applications also exist for process monitoring within the food/beverage, petroleum, and chemical industry.