Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (09): 2468-2472.doi: 10.3866/PKU.WHXB20100923

• PHOTOCHEMISTRY AND SPECTROSCOPY • Previous Articles     Next Articles

Au Nanoparticles Based Colorimetric Detection of Conformational Changes in Cytochrome c

LI Na, ZHOU Jian-Zhang, LIN Ling-Ling, HAN Nan-Nan, LIN Zhong-Hua   

  1. Key Laboratory of Physical Chemistry of Solid Surface, Department of Chemistry, College of Chemistry and Chemistry Engineering, Xiamen University, Xiamen 361005, Fujian Province, P. R. China
  • Received:2010-03-08 Revised:2010-04-22 Published:2010-09-02
  • Contact: ZHOU Jian-Zhang
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20603027, 20423002).


The colors of Au nanoparticles (Au NPs) change along with conformational changes in cytochrome c (Cyt c). We exploited this property for the colorimetric detection of Cyt c conformational changes induced by H+ and L-cysteine (L-Cys). We improved the conventional procedure for this detection. After the addition of Cyt c within different pH values, the Au NPs are either cyan, blue, purple or red. This indicates that the Au NPs can be applied to the rapid colorimetric detection of pH-induced conformational changes in Cyt c. At pH 7 the color of Au NPs changes from purple to blue and then cyan upon the addition of L-Cys, which suggests that the Au NPs can be used for the colorimetric detection of Cyt c conformational changes caused by interaction with L-Cys. The conformational changes of Cyt c were verified by circular dichroism (CD) spectroscopy. The relationship between the aggregation states and colors of the Au NPs after the addition of Cyt c was characterized by UV-Vis absorption spectroscopy and scanning electron microscopy (SEM).

Key words: Au nanoparticle, Colorimetric detection, Conformational changes of Cyt c, pH value, L-Cys