J. Tang thanks the support of the Academia Sinica and National Science Council of Taiwan under the program no. 99-2221-E-001-002-MY3 and 99-2113-M-001-023-MY3. Electronic supplementary material Additional file 1: Figures S1 to S3: Figure S1. X-ray photoelectron spectroscopy (XPS) high-resolution spectra of C (1s) and S (2p) for MUA (a

and b). Figure S2. (a) UV-visible-IR extinction spectra of representative GNR-MUA added with NaCl. (b) The dependence of the LSPR shift upon the concentration of NaCl. Figure S3. Reversibility of LSPR shift from unwashed GNR-MUA between pH 6.31 and 10.65. (DOC 188 KB) References 1. Zijlstra MK5108 P, Orrit M: Single metal nanoparticles: optical detection, spectroscopy and applications. Rep Prog Phys 2011, 74:106401.CrossRef 2. Giljohann DA, Seferos DS, Daniel WL, Massich MD, Patel PC, Mirkin CA:

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