Abstract
Herein, a composite structure, consisting of Cu nanoparticles (NPs) deposited onto carbon nanotubes and modified with ferrocene-branched chitosan, was prepared in order to develop a nonenzymatic electrochemical glucose biosensor ferrocene-chitosan/carbon nanotube@ Cu (Fc-CHIT/CNT@Cu). The elemental composition of the carbon nanohybrids, morphology and structure were characterized by various techniques. Electrochemical impedance spectroscopy (EIS) was used to study the interfacial properties of the electrodes. Cyclic voltammetry (CV) and chronoamperometry methods in alkaline solution were used to determine glucose biosensing properties. The synergy effect of Cu NPs and Fc on current responses of the developed electrode resulted in good glucose sensitivity, including broad linear detection between 0.2 mM and 22 mM, a low detection limit of 13.52 μM and sensitivity of 1.256 μA mM−1cm−2. Moreover, the modified electrode possessed long-term stability and good selectivity in the presence of ascorbic acid, dopamine and uric acid. The results indicated that this inexpensive electrode had potential application for non-enzymatic electrochemical glucose detection.
Highlights
Today, diabetes is a worldwide health problem
The Fc-CHIT spectrum showed a new absorption band at 481 cm−1 due to the M-ring extension and ring inclination of the ferrocene group. Another absorption band at 890 cm−1 indicated that the ferrocene group was present in Fc-CHIT
These results indicated that Fc-CHIT/CNT@Cu was beneficial to the conductivity of the enzyme-free glucose sensor with good selectivity, and it could reduce the interference of electroactive substances, which is more favorable to practical applications
Summary
The literature states that there were 451 million (18–99 years) people around the world suffering from diabetes in 2017, and this number is estimated to be 693 million by 2045. It is important to measure blood glucose levels during treatment of diabetes, especially in the early stages. In this case, new, more rapid, sensitive and selective glucose concentration detection methods are urgently needed. A literature survey found that glucose sensors can be divided into two categories: enzyme-based sensors [5,6] and enzyme-free sensors [7,8]. More concern has been brought to developing non-enzymatic electrochemical methods with high sensitivity, low detection limit, fast response speed, high reliability and good selectivity. Various glucose sensors, based on nanomaterials’ electrocatalytic action, have made up for the deficiency of traditional enzyme-based sensors
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