Glucose biosensor based on immobilization of glucose oxidase on a carbon paste electrode modified with microsphere-attached l-glycine

Biotechnol Appl Biochem. 2017 Sep;64(5):745-753. doi: 10.1002/bab.1533. Epub 2017 Apr 18.

Abstract

In the present study, a novel biosensor that is sensitive to glucose was prepared using the microspheres modified with (4-formyl-3-methoxyphenoxymethyl)polystyrene (FMPS) with l-glycine. Polymeric microspheres having Schiff bases were prepared from FMPS using the glycine condensation method. Glucose oxidase enzyme was immobilized onto modified carbon paste electrode by cross-linking with glutaraldehyde. Oxidation of enzymatically produced H2 O2 (+0.5 V vs. Ag/AgCl) was used for determination of glucose. Optimal temperature and pH were found as 50 °C and 8.0, respectively. The glucose biosensor showed a linear working range from 5.0 × 10-4 to 1.0 × 10-2 M, R2 = 0.999. Storage and operational stability of the biosensor were also investigated. The biosensor gave perfect reproducible results after 20 measurements with 3.3% relative standard deviation. It also had good storage stability.

Keywords: Schiff base; biosensor; carbon paste; glucose oxidase; microsphere; polystyrene.

MeSH terms

  • Biosensing Techniques / methods*
  • Blood Glucose / analysis*
  • Carbon / chemistry
  • Electrodes
  • Enzymes, Immobilized / chemistry
  • Enzymes, Immobilized / metabolism*
  • Glucose Oxidase / chemistry
  • Glucose Oxidase / metabolism*
  • Glycine / chemistry
  • Humans
  • Hydrogen-Ion Concentration
  • Limit of Detection
  • Linear Models
  • Microspheres*
  • Models, Biological
  • Polystyrenes
  • Reproducibility of Results
  • Temperature

Substances

  • Blood Glucose
  • Enzymes, Immobilized
  • Polystyrenes
  • Carbon
  • Glucose Oxidase
  • Glycine