Research on optical fiber SPR sensing characteristics of surface-enhanced fluorescence

An optical fiber-type fluorescence sensor based on surface-enhanced fluorescence (SEF) is proposed and analyzed through the finite element method. The field enhancement property of the designed multimode SPR fiber is utilized to improve the excitation rate of fluorescent molecules, which improves the sensitivity of fluorescence detection. Because the gold film is too close to fluorescent biomolecules, which can lead to fluorescence quenching, an optically transparent layer is added between the surface of the gold nanofilm and fluorescent biomolecules. And then analyze the layer's material and thickness parameters. When the gold film and PDMS thicknesses are 50 nm and 60 nm, the field enhancement factor (T) reaches the maximum value of 9.45. This fluorescence enhancement method provides a design possibility for improving the fluorescence detection sensitivity.