Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (01): 233-240.doi: 10.3866/PKU.WHXB20110125

• PHYSICAL CHEMISTRY OF MATERIALS • Previous Articles     Next Articles

Preparation of Aminopyridine Grafted Carbon Nanotube and Its Interaction with Horseradish Peroxidase

HAO Ping1, GAO Yun-Yan1, OU Zhi-Ze1, LI Yi2, WANG Zhong-Li1, WANG Xue-Song2   

  1. 1. Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi′an 710072, P. R. China;
    2. Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry,Chinese Academy of Sciences, Beijing 100190, P. R. China
  • Received:2010-08-17 Revised:2010-11-23 Published:2010-12-31
  • Contact: GAO Yun-Yan, OU Zhi-Ze E-mail:gaoyunyan@nwpu.edu.cn, ouzhize@nwpu.edu.cn
  • Supported by:

    The project was supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education, China (N9YK0003, N9YK0005), Northwestern Polytechnical University (NPU) Foundation for Fundamental Research, China (NPU-FFR-JC200822), and Ao Xiang Foundation for Youth NPU Teachers, China (07XE0152).

Abstract:

Carboxylic-functionalized multiwalled carbon nanotube (MWCNT-COOH) is obtained by oxidation with potassium bichromate and further modification by amide condensation afforded aminopyridine-grafted MWCNT (MWCNT-AP). The MWCNT-AP was characterized by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (1H-NMR) and X-ray photoelectron spectroscopy (XPS). Transmission electron microscopy (TEM) results suggest that MWCNTCOOH aggregates in ethanol and that MWCNT-AP is stable and well dispersed in solution. Horseradish peroxidase (HRP) physically adsorbed onto the surfaces of MWCNT-AP and MWCNT-COOH and the adsorption amounts were 187.5 and 153.0 μg·mg-1, respectively. UV-Vis spectra showed that the Soret band of HRP red-shifted markedly after adsorption onto MWCNT-AP or MWCNT-COOH indicating that the binding site of MWCNT-AP or MWCNT-COOH is near the heme pocket of HRP. Circular dichroism spectral results demonstrate that the secondary structure of HRP is influenced by MWCNT-AP. Enzyme-kinetic studies show that MWCNT-AP may adsorb HRP and its substrate 3,3',5,5'-tetramethylbenzidine (TMB) effectively, and the maximum reaction rate (Vmax) of HRP increases significantly after interaction with MWCNT-AP.

Key words: Carbon nanotube, Surface functionalization, Horseradish peroxidase, Catalytic activity of enzyme, Hydrogen bonding

MSC2000: 

  • O647