A modular phase transfer and ligand exchange protocol for quantum dots

Joshua Zylstra, Jennifer Amey, Nathaniel J. Miska, Lisa Pang, Corey R. Hine, Julia Langer, Robert Patrick Doyle, Mathew M Maye

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

In this paper, we describe a quantum dot (qdot) phase transfer protocol using ligand exchange and the amino acid histidine. The phase transfer from nonpolar solvents to aqueous buffers is homogeneous, and no appreciable precipitation occurs. The molecule histidine was chosen in order to first displace the organic encapsulation and second to provide a weakly chemisorbing intermediate at the qdot ionic interface. This allows the histidine to act as an intermediate shell upon which further direct ligand exchange can occur. Since this intermediate encapsulation is easily displaced by an assortment of different molecules while in aqueous buffers, we refer to this approach as modular. Characterization via FTIR and NMR revealed the extent of ligand exchange, and provides insights into the interfacial binding mechanism. The colloidal stability and photostability of the qdots was probed via UV-vis and steady state fluorescence, which revealed promising quantum yield stability of greater than 1 year. The qdots have hydrodynamic diameters of <12 nm and surface charges dependent upon ligand type and coverage. The modularity of this approach is shown by tailoring the qdot surface charge via sequential ligand exchange using mixed monolayers of carboxylic acid and poly(ethylene glycol)-terminated thiols.

Original languageEnglish (US)
Pages (from-to)4371-4379
Number of pages9
JournalLangmuir
Volume27
Issue number8
DOIs
StatePublished - Apr 19 2011

Fingerprint

Semiconductor quantum dots
Ligands
quantum dots
histidine
ligands
Histidine
Surface charge
Encapsulation
Buffers
buffers
modularity
Molecules
Quantum yield
Carboxylic Acids
Carboxylic acids
Sulfhydryl Compounds
thiols
carboxylic acids
Polyethylene glycols
amino acids

ASJC Scopus subject areas

  • Electrochemistry
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Materials Science(all)
  • Spectroscopy

Cite this

Zylstra, J., Amey, J., Miska, N. J., Pang, L., Hine, C. R., Langer, J., ... Maye, M. M. (2011). A modular phase transfer and ligand exchange protocol for quantum dots. Langmuir, 27(8), 4371-4379. https://doi.org/10.1021/la104542n

A modular phase transfer and ligand exchange protocol for quantum dots. / Zylstra, Joshua; Amey, Jennifer; Miska, Nathaniel J.; Pang, Lisa; Hine, Corey R.; Langer, Julia; Doyle, Robert Patrick; Maye, Mathew M.

In: Langmuir, Vol. 27, No. 8, 19.04.2011, p. 4371-4379.

Research output: Contribution to journalArticle

Zylstra, J, Amey, J, Miska, NJ, Pang, L, Hine, CR, Langer, J, Doyle, RP & Maye, MM 2011, 'A modular phase transfer and ligand exchange protocol for quantum dots', Langmuir, vol. 27, no. 8, pp. 4371-4379. https://doi.org/10.1021/la104542n
Zylstra J, Amey J, Miska NJ, Pang L, Hine CR, Langer J et al. A modular phase transfer and ligand exchange protocol for quantum dots. Langmuir. 2011 Apr 19;27(8):4371-4379. https://doi.org/10.1021/la104542n
Zylstra, Joshua ; Amey, Jennifer ; Miska, Nathaniel J. ; Pang, Lisa ; Hine, Corey R. ; Langer, Julia ; Doyle, Robert Patrick ; Maye, Mathew M. / A modular phase transfer and ligand exchange protocol for quantum dots. In: Langmuir. 2011 ; Vol. 27, No. 8. pp. 4371-4379.
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