Direct characterization of polymer encapsulated CdSe/CdS/ZnS quantum dots

SURFACE SCIENCE

卷:648

Article

Zorn, Gilad^1,2,4  Dave, Shivang R.^1,3,5  Weidner, Tobias^1,3,6  Gao, Xiaohu^1,3  Castner, David G.^1,2,3 

[1] Univ Washington, Natl ESCA, Seattle, WA 98195 USA

[2] Univ Washington, Dept Chem Engn, Seattle, WA 98195 USA

[3] Univ Washington, Dept Chem Engn, Dept Bioengn, Seattle, WA 98195 USA

[4] GE Global Res, One Res Circle, Niskayuna, NY 12309 USA

[5] MIT, Madrid MIT M Vis Consortium, 77 Massachusetts Ave, Cambridge, MA 02139 USA

[6] Max Planck Inst Polymer Res, Ackermannweg 10, Mainz, Germany

关键词: Quantum dots;    X-ray photoelectron spectroscopy;    Sum frequency generation;   

DOI  :  10.1016/j.susc.2015.10.013

来源: Elsevier

【 摘 要 】

Surface engineering advances of semiconductor quantum dots (QDs) have enabled their application to molecular labeling, disease diagnostics and tumor imaging. For biological applications, hydrophobic core/shell QDs are transferred into aqueous solutions through the incorporation of water-solubility imparting moieties, typically achieved via direct exchange of the native surface passivating ligands or indirectly through the adsorption of polymers. Although polymeric encapsulation has gained wide acceptance, there are few reports addressing the characterization of the adsorbed polymers and existing theoretical analyses are typically based on simple geometric models. In this work, we experimentally characterize and quantify water-soluble QDs prepared by adsorption of amphiphilic poly(maleic anhydride-alt-1-tetradecene) (PMAT, MW similar to 9000) onto commercially available CdSe/CdS/ZnS (CdSe/CdS/ZnS-PMAT). Using X-ray photoelectron spectroscopy (XPS) we determined that similar to 15 PMAT molecules are adsorbed onto each QD and sum frequency generation (SFG) vibrational spectra were utilized to investigate the mechanism of interaction between PMAT molecules and the QD surface. Importantly, when employed together, these techniques constitute a platform with which to investigate any polymer-nano particle complex in general. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

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