Progress in the preparation of new carbon nano-material modified electrodes and their application was achieved by the drug molecule recognition research group of the Key Laboratory of Chemistry of Northwestern Plant Resources, CAS, / Key Laboratory for Natural Medicines of Gansu province, Lanzhou Institute of Chemical Physics, CAS.
The modified pyrolytic graphite electrode has been prepared from high-quality rhodium nanoparticle-loaded carbon nanofibers (nano-Rh/CNF) synthesized in one step with the electrospinning technology. The modified electrode shows high electrocatalytic activity for hydrazine which is a kind of environmental pollutant. The amperometric method is applied for the rapid and accurate determination of hydrazine.The linear relationship between the catalytic current and hydrazine concentration is researched. The nano-Rh/CNF/Nafion/PGE displays a good linear response ranging from 5×10-7 M to 1.75×10-4 M, which is better than that of the latest report. The new hybrid material can be potentially used for the amperometric sensing of hydrazine with high sensitivity, good selectivity and strong anti-interference ability.
The work was published in the recent issue of Electrochemistry Communications (Electrochemistry Communications 2010, 12, 422-426).
Preparation procedure of nano-Rh/CNF
SEM image (A) and TEM image (B) of the as-made nano-Rh/CNF
(A) Current-time record of the nano-Rh/CNF/Nafion/PGE by successively adding different concentration hydrazine solution; (B) i-t current of the proposed electrode by successively adding interfering species.
Carbon nano-material can be applied widely in electrochemical sensors and biosensors due to its some excellent properties, such as large surface area, high electrical conductivity, easy modification, high chemical inertness, low cost, etc. In recent years, aiming at building new bio-electrochemical sensors based on molecular recognition, the research group has carried out a series of work on the preparation of various carbon nano-material-modified electrodes which can be used as high active supports for synthetic receptors and their electrochemical properties. The ordered mesoporous carbon-modified pyrolytic graphite electrode, mesopore-rich active carbon-modified pyrolytic graphite electrode and noble metal/carbon nano-tube composite material-modified electrode were prepared successively. The nano-Rh/CNF/Nafion/PGE and nano-Ag/CNF/Nafion/PGE were also obtained in one step with the electrospinning technology. Based on the evaluation of the electrochemical properties of the modified electrodes, the electroanalysis and sensing properties of theses modified electrodes on small biomolecules, drug molecules and pollutant molecules have been investigated as well.
The results indicate that the new carbon nano-materials have greatly improved the electron transfer capability and electrocatalytic ability on the electrode surface and promoted the electron transfer of biomolecules, drug molecules and pollutant molecules on the electrode surface. They can significantly reduce the electrolyzed oxidation of molecules, increase oxidative peak current and improve the sensitivity and selectivity of sensors as well.
The series of studies have been published in the most influential journal in electroanalysis and sensors--Biosensors and Bioelectronics (Biosensors and Bioelectronics, 2009, 24, 3391-3394), Electrochimica Acta (Electrochimica Acta, 2010, 55, 2799-2804), Talanta (Talanta, 2009, 78, 1211-1214), Electroanalysis (Electroanalysis, 2009, 21, 1200-1206) and Journal of Electroanalytical Chemistry (Journal of Electroanalytical Chemistry, 2009, 633, 264-267).
The current work is significant for the further research on the preparation of biological functionalized modified electrode of nano-materials and bio-electrochemical sensors.