Graphene and tricobalt tetraoxide nanoparticles based biosensor for electrochemical glutamate sensing

Abstract

An amperometric biosensor based on tricobalt tetraoxide nanoparticles (Co₃O₄), graphene (GR), and chitosan (CS) nanocomposite modified glassy carbon electrode (GCE) for sensitive determination of glutamate was fabricated. Scanning electron microscopy was implemented to characterize morphology of the nanocomposite. The biosensor showed optimum response within 25 s at pH 7.5 and 37 °C, at +0.70 V. The linear working range of biosensor for glutamate was from 4.0 × 10⁻⁶ to 6.0 × 10⁻⁴ M with a detection limit of 2.0 × 10⁻⁶ M and sensitivity of 0.73 μA/mM or 7.37 μA/mMcm². The relatively low Michaelis–Menten constant (1.09 mM) suggested enhanced enzyme affinity to glutamate. The glutamate biosensor lost 45% of its initial activity after three weeks.

Keywords:

• Amperometry
• biosensor
• Co₃O₄
• glutamate
• graphene

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Funding information

We gratefully acknowledge the financial support of Ankara University Research Fund (Project No: 13L4240002) and a scholarship for B. DALKIRAN of The Scientific and Technological Research Council of Turkey.