Highly-sensitive and reflective glucose sensor based on optical fiber surface plasmon resonance.

• A highly-sensitive and reflective glucose sensor was proposed and demonstrated. • The GOD was uniformly and firmly fixed on the surface of the metal film through covalent binding method. • The proposed sensor head is reflective, which is suitable for remote sensing. A reflective optical sensor based on surface plasmon resonance (SPR) was proposed to measure the glucose concentration. The gold film was sputtered on the surface of plastic cladding optical fiber to excite SPR and reflect light at the same time, making the SPR sensor highly sensitive to the variation of surrounding refractive index. Then, glucose oxidase (GOD) was adopted as the sensitive film of glucose and covalently bonded on the gold film. The enzymatic reaction between the GOD and the glucose led to the change of refractive index around the optical fiber sensor, and then cause a shift of the SPR spectrum. Therefore, the glucose concentration could be obtained by monitoring the shift of the resonance wavelength. Experimental results showed that the measurement sensitivity of the SPR sensor could reach 85.4 nm/(mg/mL) (for glucose concentration) with good selectivity and stability, which has great potential application in biomedicine and human health monitoring. [ABSTRACT FROM AUTHOR]