pH-dependent surface-enhanced Raman scattering of aromatic molecules on graphene oxide

Authors

  • Zhiming Liu,

    1. MOE Key Laboratory of Laser Life Science and Laboratory of Photonic Chinese Medicine, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China
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  • Shaoxin Li,

    1. MOE Key Laboratory of Laser Life Science and Laboratory of Photonic Chinese Medicine, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China
    2. School of Information Engineering, Guangdong Medical College, Zhanjiang, P.R. China
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  • Chaofan Hu,

    1. Department of Chemistry and Institute of Nanochemistry, Jinan University, Guangzhou, P.R. China
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  • Wen Zhang,

    1. MOE Key Laboratory of Laser Life Science and Laboratory of Photonic Chinese Medicine, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China
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  • Huiqing Zhong,

    1. MOE Key Laboratory of Laser Life Science and Laboratory of Photonic Chinese Medicine, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China
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  • Zhouyi Guo

    Corresponding author
    • MOE Key Laboratory of Laser Life Science and Laboratory of Photonic Chinese Medicine, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China
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Zhouyi Guo, MOE Key Laboratory of Laser Life Science and Laboratory of Photonic Chinese Medicine, College of Biophotonics, South China Normal University, Guangzhou 510631, Guangdong, China.

E-mail: ann@scnu.edu.cn

Abstract

Graphene has become an ideal substrate for surface-enhanced Raman scattering (SERS) to study the chemical enhancement mechanism. In comparison with mechanically exfoliated graphene, graphene oxide (GO) has been found to be a better substrate due to its highly negatively charged oxygen functional groups. In this work, the pH-dependent SERS effect of aromatic molecules on GO are investigated. The results demonstrate that the Raman enhancement of dyes deposited on GO performs differently over a wide range of pH values (2 to 10). Adsorption experiments show that the pH-dependent SERS effect is closely related to the adsorption of aromatic molecules on GO, which is dominated by the electrostatic interaction. Thus, the influence of pH in GO-mediated SERS should be carefully considered, especially in its biomedical application. Copyright © 2012 John Wiley & Sons, Ltd.

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