Sensitivity enhancement of evanescent wave immunoassay

Abstract
A fluoro-immunosensor has been developed using evanescent wave technology. The system uses a disposable device consisting of the waveguide and the flow cell. The effect of an excitation wavelength on the sensitivity of an evanescent wave immunoassay system has been studied experimentally. Background fluorescence from the polymethylmethacrylate waveguide is reduced by shifting to a longer excitation wavelength. The system using an excitation wavelength of 650 nm is found to possess sensitivity an order of magnitude higher than that obtained in conventional systems.