A New Strategy to Pretreat Carbon Nanofiber and Its Application in Determination of Dopamine

Dong Liu,Haoqing Hou,Yang Liu,Tianyan You

doi:10.1155/2010/659207

Abstract

A novel sonochemical process, using hydrogen peroxide in a laboratory ultrasonic bath, was employed to pretreat the carbon nanofiber (CNF) for creating oxygen‐rich groups on the surface of CNF. After the sonochemical process, the CNF showed good hydrophilicity and high electrochemical activity. Compared to normal pretreatment process, this sonochemical process is timesaving and effective for dispersion and functionalization of CNF. The resulting CNF showed high catalytic activity toward the oxidation of DA. A carbon paste electrode modified by CNF (CPE‐CNF) was used to determine the dopamine (DA) in the presence of ascorbic acid (AA). The detection limit is 0.05 μM, with the linear range from 0.05 μM to 6.4 μM.

Highlights

Carbonaceous materials, especially carbon nanotube (CNT), attracted great research interests, and lots of investigations have been done in the field of chemical biosensors and fuel cells
The results indicated that the aldehydic groups formed on the CNT after treated with the H2O2 solution, but the hydroxyl bands (– OH) and the aldehydic groups (< C=O) formed after treated with the acidic mixture solution
The modified electrode prepared by a simple procedure was applied to investigate the electrochemical performance of carbon nanofiber (CNF) by using 5 mM [Fe(CN)6]3−/4− redox probe

Summary

Introduction

Carbonaceous materials, especially carbon nanotube (CNT), attracted great research interests, and lots of investigations have been done in the field of chemical biosensors and fuel cells. It is necessary to treat CNF for improving the hydrophilicity. Acidic mixture solution is mostly used to treat CNF. It is necessary to develop a new way to treat CNF for improving the hydrophilicity, which should be simple and effective. At a physiological pH, DA (pKa = 8.9) is positively charged, yet AA (pKa = 4.2) is negatively charged, when the electrode surface is negatively charged, DA can be adsorbed and detected selectively [10]. Comparing with normal acid pretreatment, this method is timesaving, and the resulting CNF shows good hydrophilicity. The CNF-modified carbon paste electrode (CNF-CPE) shows high electrochemical activity and large ab Current (μA). The CNF-CPE exhibits good electrochemical catalysis toward DA in the presence of AA and it can detect DA sensitively and selectively.

Experiment

Results and Discussion

Conclusions