Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (06): 1313-1319.doi: 10.3866/PKU.WHXB201203292


Effects of Silver Nanoparticles with Different Electrical Properties on the Spectroscopic Properties of Methyl Orange

WANG Yue-Hui1, SHEN Jian-Hong2   

  1. 1. Department of Chemistry and Biology, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402, Guangdong Province, P. R. China;
    2. School of Materials Science and Engineering, Henan University of Technology, Zhengzhou 450001, P. R. China
  • Received:2012-02-07 Revised:2012-03-28 Published:2012-05-17
  • Contact: WANG Yue-Hui
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (50272032), Natural Science Foundation of Guangdong Province, China (7300212), Scientific Research Initial Foundation of University of Electronic Science and Technology of China Zhongshan Institute, China (407YKQ06), and Doctor Foundation of Henan University of Technology, China (150060).

Abstract: The effects of positive/negative silver nanoparticles on the spectroscopic properties of methyl orange (MO) in solution at different pH values were studied by UV-visible (UV-Vis) absorption spectroscopy and fluorometry. New complexes were formed by the strong electrostatic interaction between positive silver nanoparticles (P-Ag) and the MO so that UV-Vis absorption spectra showed the performance of the complexes. However, the UV-Vis absorption spectra only showed superposition of component peaks after addition of negative silver nanoparticles (N-Ag) to MO solution because of the weak interaction between N-Ag and MO induced by electrostatic repulsion. S1S0 was significantly enhanced in the MO solution containing P-Ag. The largest and smallest fluorescence enhancement ratios were observed at pH 2.1 and 4.8, respectively. The fluorescence intensity of S2S0 decreased and was almost independent of pH. Similar trends were observed for the MO solution containing N-Ag, except that the intensity of S1S0 was slightly enhanced in the presence of a small amount of N-Ag. The effects of silver nanoparticles with different electrical properties on the spectroscopic properties of MO depend on the interaction between MO and the silver nanoparticles as well as local field enhancement and non-radiative energy transfer.

Key words: Silver nanoparticle, Methyl orange, Local field enhancement, Fluorescence enhancement, Electrical property


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