Early attempts to obtain ITO nanoparticles by the co-precipitation approach in aqueous media generally led to nanoparticles FDA approved Drug Library concentration with broad size distribution and poor colloidal stability [22, 23]. Niederberger and co-workers suggested that the nonaqueous route involving solvothermal treatments of metal precursors in benzyl alcohol may result in relatively uniform

crystalline ITO nanoparticles [24]. A few recent studies demonstrated that quality colloidal ITO nanocrystals could be obtained by nonaqueous approaches [25–30]. It is noteworthy that in 2009, Masayuki and co-workers reported the synthesis of ITO nanocrystals with tunable surface plasmon resonance (SPR) peaks by controlling the concentrations of tin doping [28]. This finding is the first example of tunable

SPR in the near-infrared (NIR) region for oxide nanoparticles. The strong SPR in the NIR region of ITO nanocrystals arising from the presence of high concentrations of free carriers was confirmed by Radovanic and co-workers [30]. BMS345541 In a recent publication, the Milliron group further suggested that the localized surface plasmons of ITO nanocrystal films could be dynamically controlled by electrochemical modulation of the electron concentrations, which is promising for future development of energy-saving coating on smart windows [31]. Here we provide a detailed study on the synthesis and characterization of quality monodisperse colloidal ITO nanocrystals with characteristic and tunable SPR peaks in the NIR region. The molecular mechanism of the synthetic method developed by Masayuki et al., which will be called as the Masayuki method in the following text for the sake of

presentation, was probed using the Fourier transform infrared spectroscopy (FTIR) technique. The resulting understanding inspired us to modify the synthetic procedures and design a hot-injection approach to synthesize ITO nanoparticles. The key features of the ITO nanocrystals from the hot-injection approach including valance states of tin SU5402 research buy dopants and molar extinction coefficient were identified. We further applied the hot-injection approach to the Astemizole synthesis of ITO nanocrystals with a broad range of tin dopants and developed multiple injection procedures, aiming to achieve size control of the products. Methods Material Indium acetate and tin(II) 2-ethylhexanoate were purchased from Sigma-Adrich (St. Louis, MO, USA). ODE, n-octylether, and oleylamine were purchased from Acros Organics (Fair Lawn, NJ, USA). Tetrachloroethylene (C2Cl4) and 2-ethylhexanoic acid were purchased from Alfa Aesar (Ward Hill, MA, USA). Hydrochloric acid (HCl), ethyl acetate, and n-hexane were analytical grade reagents from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). All chemicals were used without further purification.