Immobilized optical fiber microprobe for selective and high sensitive glucose detection

Optical fiber microprobe functionalized with Glucose oxidase (GOD) has been proposed for bio-selective and high-sensitive glucose detection. Taking advantages of the free amine groups of 3-aminopropyl- triethoxysilane (APTES), the enzymes (GOD) are immobilized on the multimode microfiber through covalent interaction. Surface characterization offered by optical microscopy, scanning electron microscope and multiphoton laser scanning microscopy provide detailed evidences about the effect of the bio-functionalization. The fabricated microfiber sensor is immersed into glucose solutions at different concentrations to record and analyze the transmission spectrums from an optical sensing interrogator. The experimental results demonstrate that the resonant wavelength shift is linearly correlated with the glucose concentration in the range of 0-3.0 mg/ml with a response coefficient of 1.74 nm/mg−1 ml−1. Meanwhile, the reported sensor is also proved to be of practical utility by accurately detecting glucose content in animal serum samples. Due to the small size, label-free sensing capacity and excellent practicality, the proposed device has great potential to be applied in the fields like disease diagnosis, clinical analysis and food safety.