Fiber optic SPR sensor for liquid concentration measurement

A novel chemical method based on silver mirror reaction is proposed to fabricate the optic fiber surface plasmon resonance sensing probe for liquid concentration measurement. Compared to traditional physical methods, this chemical method is more convenient, resources conservation and inexpensive. And it does not need any complicated equipment. A liquid concentration measurement system with end-reflection optic fiber SPR sensor was set up. Then the comparison experiment between darkroom environment and natural light environment was conducted. As a result, the effect from natural light was eliminated. Glycerol solutions with different volume concentrations (from 0% to 50%) were measured, and the shifts in resonance wavelength were obtained. The sensitivity of the sensor is found to range from 346.7 nm/% to 890.7 nm/%.