The interaction of protein with solid surface is not only a fundamental phenomenon but also the key to several applications improtantly and novelly.The immobilization of functional proteins to a solid support is greatly important for biosensors and biochips.In this work

FITC labeled antibody was covalently immobilized on silicon surfaces modified by 3-aminopropyltriethoxysilane (APTES) and glutaraldehyde.The fluorescence spectra of absorption and covalent immobilization FITC labeled antibody was investigated.Subsequently

immobilizing human IgGbound FITC-goat anti-human IgG fluorescence immunoassay were obtained.The results showed that the fluorescence intensity of FITC labeled antibody on covalently immobilized surface was 6 times lager than that on absorption surface.9 nm and 4 nm red-shift at the peak of FITC fluorescence was observed on covalently immobilized surface and adsorption surface

respectively.But 3~4 nm red-shift at the peak of FITC fluorescence was obtained in the fluorescence immunoassay.Finaly

stability of covalently immobilized antibody was studied.The results indicated covalently immobilized antibodies larger than absorbed antibodies on fiber optic surface.And the interaction between immobilizing FITC-labeled antibody and fiber optic surface on covalently immobilization fiber optic surface stronger than that on absorption fiber optic surface.Combining this antibody covalent immobilization methods and the fluorescence spectroscopy analysis technology has the potential to be developed into the fast and simple fluorescence immunoassay and fluorescence multilabelling detection for biosensor.