Tapered Optical Fiber Biosensor for the Detection of Anti-Gliadin Antibodies

In this paper a new fiber optic sensor for the detection of antibodies to gliadin, in order to aid the diagnosis of celiac disease, is presented. Optical fibers of 200/230 mum (core and cladding diameters respectively) were tapered to a waist diameter in the range of 15-20 mum, and then the specific antigen was deposited using the Electrostatic Self-Assembly (ESA) method. Optimal deposition parameters have been selected using an in-situ interferometric characterization technique. The high sensitivity and continuous monitoring of the proposed scheme can reduce importantly the time and serum volume required for celiac disease tests. Performance time is shorter due to the absence of many washing and blocking steps as needed in conventional methods. Additionally, the ESA method allows the construction of nanometric scale recognition surfaces on the fiber optic, which helps to create fast response sensors for real time observation of the binding process.