Tapered optical fiber biosensor for the detection of anti-gliadin antibodies

A new biosensor has been developed by coating a tapered optical fiber with an anti-gliadin antibodies (AGAs) sensitive nanofilm using the electrostatic self-assembled (ESA) monolayer technique in order to aid the diagnosis of celiac disease. Optical fibers were tapered and then the specific antigen was deposited using the ESA method which allows the construction of nanometric scale recognition surfaces on the fiber optic and helps to create fast response sensors for real time observation of the binding process. Power changes up to 6 dB have been recorded during the antibodies binding process with concentrations in the range 1–15 ppm. Optimal deposition parameters have been selected using an in situ interferometric characterization technique which allows to state the working point of the sensor accurately. The high sensitivity and continuous monitoring of the proposed scheme can reduce importantly the time and serum volume required for celiac disease tests.