[Show abstract][Hide abstract] ABSTRACT: Strongly bonded arrays of vertically aligned, multi-walled carbon nanotubes (MWNTs) have been successfully grown on Ta foils, and provide a convenient basis for fab-ricating electrodes with high conductivity and stability. The MWNT arrays were further coated by nanostructured MnO 2 through reacting with KMnO 4 solution at room temperature. The morphology of the MnO 2 /MWNT nanocomposite was characterized by scanning elec-tron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the MnO 2 is a beehive-like nanostructure that is homogeneously and densely coated on the sur-face of the MWNTs. The capacitance of the MWNT electrode was significantly increased from 0.14 to 6.81 mF cm –2 after being modified with nanostructured MnO 2 , that is, the mass-specific capacitance of the bare and MnO 2 -modified MWNTs was about 33 and 446 F g –1 , respectively. The MnO 2 /MWNT nanocomposite on Ta foils could be potential for develop-ing a supercapacitor.
[Show abstract][Hide abstract] ABSTRACT: In this communication, an amperometric glucose biosensor based on MnO2/MWNTs electrode was reported. MnO2 was homogeneously coated on vertically aligned MWNTs by electrodeposition. The MnO2/MWNTs electrode displayed high electrocatalytic activity towards the oxidation of glucose in alkaline solution, showing about 0.30 V negative shift in peak potential with oxidation starting at ca. −0.20 V (vs. 3 M KCl–Ag/AgCl) as compared with bare MWNTs electrode. At an applied potential of +0.30 V, the MnO2/MWNTs electrode gives a linear dependence (R = 0.995) in the glucose concentration up to 28 mM with a sensitivity of 33.19 μA mM−1. Meanwhile, the MnO2/MWNTs electrode is also highly resistant toward poisoning by chloride ions. In addition, interference from the oxidation of common interfering species such as ascorbic acid, dopamine, and uric acid is effectively avoided. The MnO2/MWNTs electrode allows highly sensitive, low-potential, stable, and fast amperometric sensing of glucose, which is promising for the development of nonenzymatic glucose sensor.
[Show abstract][Hide abstract] ABSTRACT: A highly sensitive and selective glucose biosensor has been constructed by using highly dispersed NiO nanoparticles supported
on well-aligned MWCNTs (NiO/MWCNTs) as sensing interface. The NiO/MWCNTs nanocomposite was synthesized by magnetron sputtering
deposition of NiO nanoparticles on vertically aligned carbon nanotubes. The nanocomposite electrode showed high electrochemical
activity towards the oxidation of glucose in 0.20M NaOH solution. At an applied potential of +0.50V, it gives a fast response
time (< 5s) and a linear dependence (R = 0.997) on the glucose concentration up to 7.0mM with an extraordinarily high sensitivity of 1.77 mAmM-1cm-2 and a detection limit of 2μM. The interference by the oxidation of common interfering species such as ascorbic acid, dopamine,
uric acid, lactose, and fructose is effectively avoided. The electrode was used to analyze glucose concentration in human
serum samples. It allows highly sensitive, stable, and fast amperometric sensing of glucose, which is promising for the development
of nonenzymatic glucose sensors.
KeywordsCarbon nanotubes-Nickel oxide-Glucose-Electroanalysis-Biosensor