A Simple Layer-by-Layer Assembly Strategy for a Reagentless Biosensor Based on a Nanocomposite of Methylene Blue-Multiwalled Carbon Nanotubes

作者：Zhang Yiming; Liu Lijun; Xi Fengna; Wu Tianxing; Lin Xianfu^*

来源：Electroanalysis, 2010, 22(3): 277-285.

DOI：10.1002/elan.200900307

• Multiwalled carbon nanotubes
• Reagentless biosensor
• Layer-by-layer assembly
• Methylene blue
• Hydrogen peroxide
• Nanotubes
• Biosensors

A simple layer-by-layer (LBL) assembly strategy was established for constructing a novel reagentless biosensor based on a nanocomposite of methylene blue multiwalled carbon nanotubes (MB-MWNTs). A nanocomposite of MB-MWNTs was obtained by direct premixing and possessed good dispersion in barbital-HCl buffer. Through electrostatic interactions, the nanocomposite of MB-MWNI's could alternately be assembled with horseradish peroxidase (HRP) on the An electrode modified with precursor films. UV/Vis spectra and scanning electron microscopy (SEM) were applied to reveal the formation of the nanocomposite of MB-MWNTs. The LBL assembly process was also verified by electrochemical impedance spectroscopy (EIS). The MB is a well-established mediator and efficiently facilitated the electron shuttle between the HRP and the electrode, as demonstrated by the cyclic voltammetry (CV) measurements. The as-prepared reagentless biosensor exhibited a fast response for the determination of hydrogen peroxide (H(2)O(2)) and reached 95% of the steady-state current within 3 s. It was found that the linear response range of the reagentless biosensor for H(2)O(2) was from 4.0 mu M to 3.78 mM with a detection limit of 1.0 mu M and a sensitivity of 22.5 mu A mM(-1). The biosensor exhibited a high reproducibility and stability.

• 出版日期2010-2
• 单位浙江大学