Acousto-optic tunable filter-surface plasmon resonance immunosensor for fibronectin Original Research Article

An acousto-optic tunable filter-surface plasmon resonance (AOTF-SPR) immunosensor based on wavelength-modulation was applied to detect fibronectin by direct, sandwich and colloidal Au-enhanced immunoassay. The design of the wavelength-modulation AOTF-SPR immunosensor is based on fixing the incident angle of light and measuring the reflected intensity of light in the wavelength range spanning 440–790 nm. Fibronectin was determined in the concentration range 2.5–30, 0.5–30, and 0.25–30 μg/mL for direct, sandwich and colloidal Au-enhanced immunoassay, respectively. The results demonstrate that AOTF-SPR biosensor can be applied to direct and enhanced immunoassay of biomolecule.