title: Cobalt hexacyanoferrate modified multi-walled carbon nanotubes/graphite composite electrode as electrochemical sensor on microfluidic chip.
abstract: Nanomaterial-based electrochemical sensor has received significant interest. In this work, cobalt hexacyanoferrate modified multi-walled carbon nanotubes/graphite composite electrode was electrochemically prepared and exploited as an amperometric detector for microchip electrophoresis. The prepared sensor displayed rapid and sensitive response towards hydrazine and isoniazid oxidation, which was attributed to synergetic electrocatalytic effect of cobalt hexacyanoferrate and multi-walled carbon nanotubes. The sensitivity enhancement with nearly two orders of magnitude was gained, compared with the bare carbon paste electrode, with the detection limit of 0.91 μM (S/N=3) for hydrazine. Acceptable repeatability of the microanalysis system was verified by consecutive eleven injections of hydrazine without chip and electrode treatments, the RSDs for peak current and migration time were 3.4% and 2.1%, respectively. Meanwhile, well-shaped electrophoretic peaks were observed, mainly due to fast electron transfer of electroactive species on the modified electrode. The developed microchip-electrochemistry setup was successfully applied to the determination of hydrazine and isoniazid in river water and pharmaceutical preparation, respectively. Several merits of the novel electrochemical sensor coupled with microfluidic platform, such as comparative stability, easy fabrication and high sensitivity, hold great potential for hydrazine compounds assay in the lab-on-a-chip system.
authors: School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, PR China.
authors: Xinchun
authors: X
authors: Li
authors: Zuanguang
authors: Z
authors: Chen
authors: Yuwen
authors: Y
authors: Zhong
authors: Fan
authors: F
authors: Yang
authors: Jianbin
authors: J
authors: Pan
authors: Yajing
authors: Y
authors: Liang
mesh_terms: D055664:Electrochemical Techniques; D004566:Electrodes; D046209:Electrophoresis, Microchip; D005295:Ferrocyanides / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006834:Hydrazines / Q000737:chemistry; D007538:Isoniazid / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D005295:Ferrocyanides; D006834:Hydrazines; D037742:Nanotubes, Carbon; C116383:ferrocyn; C029424:hydrazine; D006108:Graphite; D007538:Isoniazid