Specific detection of monosaccharide by dual-channel sensing platform based on dual catalytic system constructed by bio-enzyme and bionic enzyme using molecular imprinting polymers

摘要

Biosensors based on bio-enzymes have received enormous attention due to their unrivaled specificity in targeted molecular detection. However, catalytic activities of employed bio-enzymes could be easily deactivated in some extreme conditions such as strong acidity, alkalinity and hyperthermia, resulting in poor stability and sensitivity of the constructed biosensors. Nowadays, bionic enzymes with similar catalytic activities to bio-enzymes have been regarded as ideal alternatives to bio-enzymes for sensor fabrication. However, the deficiency in specificity severely restricts their potential applications in specific detection. Herein, a dual-channel sensing platform was successfully constructed and applied for monosaccharide (eg. glucose) detection in both weakly and strongly alkaline conditions based on the combination of bio-enzyme (glucose oxidase, GOD) and bionic enzymes (NiCO_2O_4@Fe_3O_4 particles) via molecular imprinting technique. In the constructed system, the sea urchin-shaped NiCO_2O_4 particles with huge surface area are used not only as a platform for immobilization of bionic enzyme (Fe_3O_4 NPs) and bio-enzymes (GOD) but also as bionic probes for glucose sensing in alkaline condition. NiCO_2O_4 and GOD act as the dual-channel sensing probes in the sensing process while Fe_3O_4 NPs could consume the generated H_2O_2 from glucose, thus leading to the increased sensitivity of the as-prepared biosensors. Impressively, the as-prepared sensing platform showed satisfied sensitivity in glucose detection and could specially discern glucose among its chiral isomers.