A novel low cost non-enzymatic glucose sensor based on nanoporous cobalt sulfide nanosheet arrays
A novel low cost non-enzymatic glucose sensor based on nanoporous cobalt sulfide nanosheet arrays
Aida Mofazzal Jahromi,1,*Rahil Mosallanejad,2Seyyed Ebrahim Moosavifard,3Ali Rayatinejad,4Farnaz Abbasi,5
1. Student research committee, Jahrom University of Medical Sciences, Jahrom, Iran 2. Student research committee, Jahrom University of Medical Sciences, Jahrom, Iran 3. Zoonoses Research Center, Jahrom University of Medical Sciences, Jahrom, Iran 4. Student research committee, Jahrom University of Medical Sciences, Jahrom, Iran 5. Student research committee, Jahrom University of Medical Sciences, Jahrom, Iran
Introduction: Diabetes mellitus is the ninth leading cause of death globally, which is expected to reach 366 million patients by the year 2030. Due to the risks of diabetes-induced diseases and high healthcare expenditures, which are mainly caused by lack of continuous glycemic control, finding techniques for frequent monitoring of blood glucose has become one of the main concerns of modern society. Among methods of blood glucose evaluation, electrochemical sensors are so promising for optimal therapeutic interventions as well as improving the quality of diabetic patients due to their simplicity, low cost, high accuracy, and speed. Moreover, researchers are getting more interested in developing none enzymatic sensors by reason their disposability, rigidity, stability, high sensitivity, simple synthesis process, and ability to combine them with different nanomaterials.
Methods: In this research, the nanosheets of cobalt sulfide were electrochemically (using the chronoamperometry technique at a potential of -1.2 V relative to the silver/silver chloride reference electrodedeposited on the surface of pencil graphite and used directly as a non-adhesive non-enzymatic electrode to measure glucose in a 3-electrode system. The electrocatalytic efficiency of this electrode for the oxidation of glucose in 0.1 molar sodium hydroxide electrolyte (pH=13) and in the potential of +0.55 V was evaluated using cyclic voltammetry and amperometry techniques. Also, the structure and morphology of the as-prepared electrode were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM).
Results: Electrochemical studies showed that this electrode has a linear amplitude in the range of 2 to 5000 μM, detection limit of 0.3 μM, and sensitivity of 1985 μA/mM cm2. Also, the study of the electrode responses during 3 months for a concentration of 2 mM glucose showed stability of 90.4%, which indicates high stability of this electrode. Finally, the amperometric responses of this electrode in human serum samples were compared with the commercial glucometer responses
Conclusion: A low glucose detection limit of 0.3 μM, long-term stability, wide linear amplitude, and high sensitivity, highlight the promising performance of the cobalt sulfide nanosheets on pencil graphite electrode for cost-effective non-enzymatic glucose sensing with high favorable reproducibility.