Highly sensitive flow-injection determination of glucose in plasma using an immobilized pyranose oxidase and a chemiluminometric peroxidase sensor

A flow-injection system is proposed for the determination of glucose in plasma. Chemiluminometric measurement of glucose was based on the luminol reaction with hydrogen peroxide produced by immobilized pyranose oxidase within a flow-through cell containing immobilized peroxidase. Pyranose oxidase was immobilized on toresylate-poly(vinyl alcohol) beads and packed into a stainless steel column (20 mm × 4 mm i.d.). Peroxidase is immobilized on toresylate-hydrophilic vinyl polymer beads and packed into transparent PTFE tube (20 cm × 1.0 mm i.d.). Plasma (1 μl) was diluted with water to 25 ml. Sample solution (10 μl) was injected into the carrier stream. The maximum sample throughput was 180 h−1. The calibration graph was linear from 10 nM to 5 μM glucose; the detection limit (signal to noise ratio=3) was 3 nM (5 pg in 10 μl injection). The chemiluminometric peroxidase sensor was stable for 30 days.