Voltammetric Determination of Xanthine with a Single‐Walled Carbon Nanotube‐Ionic Liquid Paste Modified Glassy Carbon Electrode
ABSTRACT Single-walled carbon nanotube (SWNT) and room temperature ionic liquid (i.e., 1-butyl-3-methylimidazolium hexaflourophosphate, BMIMPF6) were used to fabricate paste modified glassy electrode (GCE). It was found that the electrode showed sensitive voltammetric response to xanthine (Xt). The detection limit was 2.0×10−9 M and the linear range was 5.0×10−9 to 5.0×10−6 M. The electrode also displayed good selectivity and repeatability. In the presence of uric acid (UA) and hypoxanthine (Hx) the response of Xt kept almost unchanged. Thus this electrode could find application in the determination of Xt in some real samples. The analytical performance of the BMIMPF6-SWNT/GCE was demonstrated for the determination of Xt in human serum and urine samples.
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- "trode for glucose sensing . Xiao et al. constructed a carbon nanotube–ionic liquid gel modified electrode, and found that the resulting electrode possessed excellent selectivity towards the determination of xanthine . In general, ILs can improve the analytical characteristics of the modified electrodes to some extent. "
ABSTRACT: An ionic liquid (i.e. 1-butyl-3-methylimidazolium hexafluophosphate, BMIMPF6)–single-walled carbon nanotube (SWNT) paste coated glassy carbon electrode (BMIMPF6–SWNT/GCE) has been fabricated. The electrode shows good electro-catalysis to the reduction of methylparathion (MP) and MP can accumulate effectively on it. Thus, MP can produce a sensitive cathodic peak on the BMIMPF6–SWNT/GCE. Parameters influencing the voltammetric response of MP are optimized for MP determination. Under the selected experimental conditions (i.e. solution pH 7.0; accumulation time, 180 s; accumulation potential, on open-circuit; the ratio of SWNT to BMIMPF6 1:20 (mg μL−1)), the peak current is linear to MP concentration over the range of 2.0 × 10−9 to 4.0 × 10−6 M. The detection limit is 1.0 × 10−9 M. Therefore, this system is quite sensitive in comparison with other electrochemical methods. In addition, it is found that the hydrolysate of MP (i.e. p-nitrophenol, PNP) can also produce a sensitive cathodic peak under this condition. But the peaks of MP and PNP do not overlap with each other. Hence they can be determined simultaneously. This electrode has been applied to the determination of MP and PNP in real samples.Sensors and Actuators B Chemical 05/2008; 132(1-132):34-39. DOI:10.1016/j.snb.2008.01.010 · 4.29 Impact Factor
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ABSTRACT: A single-walled carbon nanotube (SWNT) paste coated glassy carbon electrode (GCE) has been prepared by using room temperature ionic liquid (i.e. 1-octyl-3-methylimidazolium hexafluorophosphate, OMIMPF6) as a binder. The electrode (i.e. OMIMPF6–SWNT/GCE) combines the features of carbon nanotube and room temperature ionic liquid. Folic acid (FA) can exhibit a very sensitive anodic peak at 0.75 V (vs SCE) in pH 5.5 phosphate buffer solutions, resulting from the irreversible oxidation of FA. Under the optimized conditions, the peak current is linear to FA concentration over the range of 2.0 × 10−9 to 4.0 × 10−6 M by using differential pulse voltammetry, and the detection limit is 1.0 × 10−9 M (S/N = 3). The OMIMPF6–SWNT/GCE is successfully applied to the determination of FA in real samples.Sensors and Actuators B Chemical 09/2008; 134(2-134):895-901. DOI:10.1016/j.snb.2008.06.037 · 4.29 Impact Factor
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ABSTRACT: A novel room temperature ionic liquid (i.e., 1-octyl-3-methylimidazolium hexafluorophosphate, OMIMPF6)-multiwall carbon nanotube (MWNT) gel-chitosan (Chi) composite modified glassy carbon electrode (GCE) was fabricated and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), infrared spectroscopy (IR), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). The OMIMPF6-MWNT gel-Chi composite showed good conductivity, stability, and extraction effect due to the synergic action of OMIMPF6, MWNT, and Chi. Furthermore, it was found that the OMIMPF6-MWNT gel-Chi composite had strong electrocatalytic effect on the oxidation of nitrite and at the OMIMPF6-MWNT gel-Chi/GCE nitrite could produce a very sensitive anodic peak. Under optimized conditions, the peak current was linear to nitrite concentration from 2.0×10−8 to 6.0×10−5 M. The detection limit was 1.0×10−8 M. The electrode also exhibited acceptable stability, repeatability and selectivity. It was used successfully for the determination of nitrite in soil, sewage and sausage samples.Electroanalysis 09/2008; 20(18):2047 - 2054. DOI:10.1002/elan.200804288 · 2.50 Impact Factor