title: Nonenzymatic glucose voltammetric sensor based on gold nanoparticles/carbon nanotubes/ionic liquid nanocomposite.
abstract: In this paper, a novel nonenzymatic glucose voltammetric sensor based on a kind of nanocomposite of gold nanoparticles (GNPs) embedded in multi-walled carbon nanotubes (MWCNTs)/ionic liquid (IL) gel was reported. The surface morphology of this nanocomposite was characterized using X-ray photoelectron spectrometer (XPS), scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. It can be found that most of GNPs lie close to the ektexine of MWCNTs and the others have obviously inserted the inner of MWCNTs through the defects or ends of MWCNTs, due to the attraction between GNPs and MWCNTs as well as the repulsion between GNPs and IL. Voltammetry was used to evaluate the electrocatalytic activities of the nanocomposite biosensor toward nonenzymatic glucose oxidation in alkaline media. The GNPs embedded in MWCNTs/IL gel have strong and sensitive voltammetric responses to glucose, owing to a possible synergistic effect among GNPs, MWCNTs and IL. Under the optimal condition, the linear range for the detection of the glucose is 5.0-120 microM with the correlation coefficient of 0.998, based on the oxidation peak observed during cathodic direction of the potential sweep. The kinetics and mechanism of glucose electro-oxidation were intensively investigated in this system. This kind of nanocomposite biosensor is also highly resistant toward poisoning by chloride ions and capable of sensing glucose oxidation in the presence of 20 microM uric acid and 70 microM ascorbic acid. This work provides a simple and easy approach to the detection of glucose in body fluid with high sensitivity and excellent selectivity.
authors.affiliation: Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhu
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Lu
authors.forename: Meixian
authors.initials: M
authors.lastname: Li
authors.forename: Yuanhua
authors.initials: Y
authors.lastname: Shao
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Zhu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D001826:Body Fluids / Q000737:chemistry; D055664:Electrochemical Techniques; D005947:Glucose / Q000032:analysis* / Q000737:chemistry; D006046:Gold; D052578:Ionic Liquids; D053768:Metal Nanoparticles; D053761:Nanocomposites / Q000737:chemistry*; D037742:Nanotubes, Carbon; D010084:Oxidation-Reduction
chemical_list: D052578:Ionic Liquids; D037742:Nanotubes, Carbon; D006046:Gold; D005947:Glucose