Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (06): 1467-1473.doi: 10.3866/PKU.WHXB20110606

• SOFT MATTER • Previous Articles     Next Articles

Interaction between Gemini and DNA at the Air/Water Interface

KANG Xue-Li, CHEN Qi-Bin, SHANG Ya-Zhuo, LIU Hong-Lai   

  1. Key Laboratory for Advanced Materials, East China University of Science and Technology, Shanghai, 200237, P. R. China
  • Received:2010-11-18 Revised:2011-03-05 Published:2011-05-31
  • Contact: CHEN Qi-Bin
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20806025, 20706013), Creative Team Development Project of Ministry of Education of China (IRT0721), Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry and Fundamental Research Funds for the Central Universities, China.


Monolayers may be obtained by an electrostatic force between cationic surfactants and anionic electrolyte deoxyribonucleic acid (DNA) molecules, and a corresponding Langmuir-Blodgett (LB) complex monolayer can be fabricated by compression and deposition of the monolayer at the air/water interface. In this work, the interaction between cationic Gemini surfactants ([C18H37(CH3)2N+-(CH2)s-N+(CH3)2C18H37]·2Br-, abbreviated 18-s-18, s=3, 4, 6, 8, 10, 12) and double-strand DNA (dsDNA)/single-strand DNA (ssDNA) was investigated by surface pressure-surface area (π-A) isotherms, atomic force microscope (AFM), and Quartz crystal microbalance (QCM). Moreover, the limiting molecular areas of 18-s-18 on different subphases were compared. We found that the spacer and the subphase greatly influence the properties of the Gemini surfactants at the air/water interface. In addition, we conclude that the adsorption capacity of the Gemini surfactants with DNA is closely related to their interaction modes.

Key words: Gemini surfactant, Deoxyribonucleic acid, π-A isotherm, Atomic force microscope, Quartz crystal microbalance