[3] Avci E, Culha M. Appl. Spectrosc., 2014, 68(8): 890.

[4] Otto A, Mrozek I, Grabhorn H, et al. J. Phys. Condensed Matter., 1992. 4(5): 1143.

[5] Novoselov K S, Geim A K, Morozov S V, et al. Science, 2004, 306(5696): 666.

[6] Marcano D C, Kosynkin D V, Berlin J M, et al. ACS Nano, 2010, 4(8): 4806.

[7] Khan U, Porwal H, Nawaz K, et al. Langmuir, 2011, 27(15): 9077.

[8] Wang C C, Chen W, Han C, et al. Sci. Rep., 2014, 4.

[9] Ling X, Zhang J. Small, 2010, 6(18): 2020.

[10] Johnson P S, Huang C S, Kim M, et al. Langmuir, 2014, 30(9): 2559.

[11] Huang C S, Kim M, Safron N S, et al. J. Phys. Chem. C, 2014. 118(4): 2077.

[12] Li X S, Zhu Y W, Cai W W, et al. Nano Lett., 2009, 9(12): 4359.

[14] Kim M, Safron N S, Huang C S, et al. Nano Lett., 2012, 12(1): 182.