Low-Temperature Approach to Highly Emissive Copper Indium Sulfide Colloidal Nanocrystals and Their Bioimaging Applications

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• 作者：Kui Yu ; Peter Ng ; Jianying Ouyang ; Md. Badruz Zaman ; Abedelnasser Abulrob ; Toya Nath Baral ; Dorothy Fatehi ; Zygmunt J. Jakubek ; David Kingston ; Xiaohua Wu ; Xiangyang Liu ; Charlie Hebert ; Donald M. Leek ; Dennis M. Whitfield
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2013
• 出版时间：April 24, 2013
• 年：2013
• 卷：5
• 期：8
• 页码：2870-2880
• 全文大小：592K
• 年卷期：v.5,no.8(April 24, 2013)
• ISSN：1944-8252

文摘

We report our newly developed low-temperature synthesis of colloidal photoluminescent (PL) CuInS₂ nanocrystals (NCs) and their in vitro and in vivo imaging applications. With diphenylphosphine sulphide (SDPP) as a S precursor made from elemental S and diphenylphosphine, this is a noninjection based approach in 1-dodecanethiol (DDT) with excellent synthetic reproducibility and large-scale capability. For a typical synthesis with copper iodide (CuI) as a Cu source and indium acetate (In(OAc)₃) as an In source, the growth temperature was as low as 160 掳C and the feed molar ratios were 1Cu-to-1In-to-4S. Amazingly, the resulting CuInS₂ NCs in toluene exhibit quantum yield (QY) of 23% with photoemission peaking at 760 nm and full width at half maximum (FWHM) of 140 nm. With a mean size of 3.4 nm (measured from the vertices to the bases of the pyramids), they are pyramidal in shape with a crystal structure of tetragonal chalcopyrite. In situ ³¹P NMR (monitored from 30 掳C to 100 掳C) and in situ absorption at 80 掳C suggested that the Cu precursor should be less reactive toward SDPP than the In precursor. For our in vitro and in vivo imaging applications, CuInS₂/ZnS core鈥搒hell QDs were synthesized; afterwards, dihydrolipoic acid (DHLA) or 11-mercaptoundecanoic acid (MUA) were used for ligand exchange and then bio-conjugation was performed. Two single-domain antibodies (sdAbs) were used. One was 2A3 for in vitro imaging of BxPC3 pancreatic cancer cells. The other was EG2 for in vivo imaging of a Glioblastoma U87MG brain tumour model. The bioimaging data illustrate that the CuInS₂ NCs from our SDPP-based low-temperature noninjection approach are good quality.

Keywords:

CuInS₂ nanocrystals; quantum dots; diphenylphosphine sulphide; in vitro imaging; in vivo imaging