Performance improvement of a glucose sensor based on fiber optic localized surface plasmon resonance and anti-aggregation of the non-enzymatic receptor

Abstract

The performance of glucose sensors based on non-enzymatic receptors is often limited because of the aggregation of receptors and the resulting lowered binding efficiency. To improve the limit of detection (LOD) in glucose sensors, a polyoligomeric silsesquioxane (POSS) is introduced as a support to enhance the binding efficiency between glucose and non-enzymatic receptor. POSS support reduces the aggregation and partially grants orientation to ensure that non-enzymatic receptors can productively react with targets. The synthesized amine@POSS-aminophenylboronic acid (APBA) conjugate was immobilized on the surface of gold nanoparticles, which were fastened on the optical fiber. Optical fiber-based sensors using localized surface plasmon resonance (LSPR) enabled rapid detection, ease of handling, and remote sensing. After confirming the response characteristics to the refractive index, a suitable concentration of amine@POSS-APBA receptor was selected for the fabricated fiber optic sensor. Glucose detection was performed at various concentrations using non-enzymatic receptors with and without POSS support. The experimental results demonstrated that increased responses were observed in the designed method than when only the non-enzymatic receptor was applied. The LOD for glucose was quantified as 25.0 μM. We believe that improved glucose sensors based on fiber optic LSPR and POSS support has the potential to be applied to field detection in various fields, such as medicine, food safety, and the environment.