Abstract
This paper proposes a novel fiber optic immunoassay biosensor based on the Fabry-Perot (F-P) interferometry. The PDMS dip coating and self-assembly monolayers coating are employed to prepare the fiber probes in the formation of F-P cavity and modification of the tip surface respectively. As the fiber probe inserting into the target solution, the immunoreaction will be introduced on the fiber tip. The covalent binding of the Rabbit IgG and Anti Rabbit IgG-Cy3 molecules on the fiber tip will contribute to the variation of the refractive index of interface as well as the reflectance. The interference spectrum will be shifted due to the reflectance variation. The time response is also implemented by taking the in-situ measurement of spectrum valley shift and the signal will reach the steady state within IS minutes. Finally, the sensitivity of this immunoassay biosensor has also been demonstrated that the lowest detectable concentration of the target sample Anti Rabbit IgG-Cy3 is 10 -12 g/ml, which is lower than the detection limit of ELISA of 5*10 -11 g/ml. This fiber optic immunoassay biosensor will be applied in the brain research for in-vivo and in-situ monitoring the biochemical reactions of the neurocytes.