J Appl Phys 2008, 103:094112. 10.1063/1.2917402CrossRef 28. McCall SL, Plat PM, Wolff PA: Surface enhanced Raman scattering. Phys Lett 1980, 77A:381–383.CrossRef 29. Cotton TM, Uphaus RH, Mobius DJ: Distance dependence of SERS: enhancement

in Langmuir-Blodgett dye multilayers. J Phys Chem 1986, 90:6071–6073. 10.1021/j100281a003CrossRef 30. Maher RC: SERS hot spots. In Raman Spectroscopy for Nanomaterials Characterization. Berlin: Springer; 2012:215–260.CrossRef 31. Kleinman SL, Frontiera RR, Henry A-I, Dieringer JA, Van Duyne RP: Creating, characterizing, and controlling chemistry with SERS hot spots. Phys Chem Chem Phys 2013, 15:21–36. SB431542 clinical trial 10.1039/c2cp42598jCrossRef 32. Borys NJ, Shafran E, Lupton JM: Surface plasmon delocalization in silver nanoparticle aggregates revealed by subdiffraction supercontinuum hot spots. Scientific Reports 2013, 3:2090. Competing interests The authors declare that they have no competing interests. Authors’ contributions SC prepared the nanoisland film samples, measured the absorption spectra, and processed the resonance shift calculations. AM deposited the TiO2 on the selleck inhibitor samples and measured the Raman spectra. AD performed the AFM studies of the samples. AAL and SH supervised the whole work. All authors read and approved the final manuscript.”
“Background Carbon

dots (C-dots) are a new member of the carbon nanomaterial family after C60, carbon nanotubes, and graphene and were firstly discovered by accident when researchers were trying to purify single-walled carbon nanotubes (SWCNTs) fabricated by arc discharge methods [1]. Since then, many studies concerning C-dots have been reported [2–4]. C-dots have attracted much attention due to their well-defined, nearly isotropic shapes together with their ultrafine

dimensions and tunable surface functionalities. Moreover, a variety of simple, fast, and cheap synthetic routes for C-dots have been developed in the past few years including arc discharge, laser ablation, VAV2 electrochemical oxidation, hydrothermal, combustion/thermal, supported synthetic, and microwave methods [4–6]. Most notable superiority, however, is their potential as replacements for toxic heavy metal-based quantum dots (QDs) which are currently intensively used and are plagued by safety concerns and known environmental hazards [2, 5, 6]. C-dots have proven themselves in various applications with photoluminescence properties comparable and even superior to those of QDs [2, 3, 7], such as high photostability, tunable emission, large two-photon excitation cross section [8, 9], and non-blinking fluorescence [10]. C-dots have been successfully applied in bioimaging [11], both in vitro [8] and in vivo [12], and even showed significant utility in multiphoton imaging [9]. Moreover, beyond these apparently straightforward applications, more complicated designs aimed at multifunctional nanosystems based on C-dots have been reported.