Roughened cylindrical gold layer with curve graphene coating for enhanced sensitivity of fiber SPR sensor

A fiber surface plasmon resonance (SPR) sensor with roughened gold film and curve graphene coating for glucose monitoring with enhanced sensitivity is proposed in the paper. This is the first attempt to employ ultrasonic cavitation to roughen the gold layer on micron-scale cylindrical surface, which could construct nanostructures on the surface of gold layer to stimulate local surface plasmon resonance (LSPR). A liquid transfer method is also first employed to curve chemical vapor deposition (CVD) graphene film to coat the roughened gold layer through Van der Waals force for promoting the electron mobility of gold and adsorption of glucose. The two novel and simple methods, which improved the sensitivity of the fiber SPR sensor remarkably, make the detection of hypoglycemia possible, which is still a big challenge for continuous glucose monitoring in clinic.