Aixia Gu

CuS nanotubes for ultrasensitive nonenzymatic glucose sensors

CuS nanotubes made up of nanoparticles were successfully prepared in large quantities in an O/W microemulsion system under low temperature; the as-prepared CuS nanotube modified electrode was used as an enzyme-free glucose sensor.

Silver oxide nanowalls grown on Cu substrate as an enzymeless glucose sensor.

Ag(2)O nanowalls consisting of densely packed nanoplates based on a Cu substrate were synthesized through a facile one-pot hydrothermal method. A new enzymeless glucose sensor of Cu-Ag(2)O nanowalls was fabricated. The Cu-Ag(2)O nanowalls showed higher catalysis on glucose oxidation than traditional Ag(2)O nanoflowers and Cu-Ag(2)O nanospindles. At an applied potential of 0.4 V, the sensor produced an ultrahigh sensitivity to glucose (GO) of 298.2 microA mM(-1). Linear response was obtained over a concentration range from 0.2 mM to 3.2 mM with a detection limit of 0.01 mM (S/N = 3). Satisfyingly, the Cu-Ag(2)O nanowalls modified electrode was not only successfully employed to eliminate the interferences from uric acid (UA) acid ascorbic (AA) and also fructose (FO) during the catalytic oxidation of glucose. The Cu-Ag(2)O nanowalls modified electrode allows highly sensitive, excellently selective, stable, and fast amperometric sensing of glucose and thus is promising for the future development of nonenzymatic glucose sensors.

Fabrication of CuO nanowalls on Cu substrate for a high performance enzyme-free glucose sensor

Enzyme-free determination of glucose on an ordered CuO nanowall-based Cu substrate modified electrode is investigated. The structure and morphology of the CuO nanowalls were characterized by X-ray diffraction and scanning electron microscopy. The growth mechanism of the sample and the influence factor of the preparation process are discussed. The electrochemical study has shown that the CuO nanowalls exhibit a higher catalytic effect on the glucose than the CuO nanosphere without Cu substrate. This may be attributed to the special structure of the nanomaterials and the substrate of the electronic conductive Cu. The amperometric response showed that the CuO nanowall-modified glassy carbon electrode has a good response for glucose with a linear range of 0.05 μM to 10 μM with a sensitivity of 0.5563 μA μM−1 in pH 9.2 phosphate buffered solutions.

Enhanced electrochemical catalytic activity of new nickel hydroxide nanostructures with (100) facet

Owing to their scientific and technological importance, inorganic single crystals with highly reactive surfaces have long been studied. Unfortunately, surfaces with high reactivity usually diminish rapidly during the crystal growth process as a result of surface energy minimization. The crystal planes of nickel hydroxide play an essential role in determining its catalytic oxidation properties. In this study, β-Ni(OH)2 nanocolumns with well-defined crystal planes have been synthesized by a facile solution-based hydrothermal method. TEM and XRD studies reveal that the assembled stacking of the Ni(OH)2 nanocrystals leads to the predominantly exposed planes as unusually reactive (100) facet rather than the stable (001) facet in the hexagonal nanoslice structures. Consequently, it is demonstrated that the β-Ni(OH)2 nanocolumns are more electrochemical catalytic active than their counterparts, nanoslices and nanoplates. The current study indicates that catalysts with well-defined reactive surface can be “designed” through controlled synthesis of nanostructures.