A Novel Electrochemiluminescence Biosensor Based on Glucose Oxidase Immobilized on Magnetic Nanoparticles

A novel electrochemiluminescence (ECL) glucose biosensor based on Fe3O4 nanoparticles is presented. Glucose oxidase (GOD) was covalently cross-linked to the surface of synthesized magnetic Fe3O4 nanoparticles. The composite particles of Fe3O4/GOD were adhered onto solid paraffin carbon paste electrode surface by magnetic force to act as a working electrode. Hydrogen peroxide was produced by enzymatic reaction of GOD, and ECL could be obtained by the reaction between luminol and hydrogen peroxide; then, a novel ECL glucose biosensor was fabricated. There was a linear relationship between ECL intensity and glucose concentration in the range of 1 × 10−5–1 × 10−2 M with a regression equation of I = 65.4374C + 23.9017 (r = 0.9987), and the detection limit was 1 μM. The ECL biosensor has shown short response time and high stability, and the electrode surface was easily renewable. The proposed biosensor has been applied for the determination of glucose in plasma samples.