Beta-cyclodextrin based reflective fiber-optic SPR sensor for highly-sensitive detection of cholesterol concentration

A fiber-optic surface plasmon resonance (SPR) cholesterol sensor is proposed and demonstrated. The sensor adopts a reflective structure and uses a gold film to excite the SPR. Through esterification reaction, the beta-cyclodextrin is fixed on the gold film of the fiber-optic sensor. When the cholesterol concentration changes, the sensitive membrane structure changes and the resonant wavelength of the SPR sensor generates a red shift, so the cholesterol concentration can be measured through monitoring the wavelength shift of the SPR resonance spectrum. Experiment results showed that when the cholesterol concentration was 0 μM–0.05 μM, the shift of the resonance wavelength was linear with the change of cholesterol concentration with high sensitivity of 156.18 nm/μM. The sensor is simple, green and sensitive, and has good potential applications in biomedicine.