Engineering fluorescent gold nanoclusters using xanthate-functionalized hydrophilic polymers: Toward enhanced monodispersity and stability

Veerasikku Gopal Deepagan, Meike N. Leiske, Nicholas L. Fletcher, David Rudd, Terence Tieu, Nicholas Kirkwood, Kristofer J. Thurecht, Kristian Kempe, Nicolas H. Voelcker, Anna Cifuentes-Rius

Research output: Contribution to journalArticleResearchpeer-review

Abstract

We introduce xanthate-functionalized poly(cyclic imino ethers)s (PCIEs), specifically poly(2-ethyl-2-oxazoline) and poly(2-ethyl-2oxazine) given their stealth characteristics, as an attractive alternative to conventional thiol-based ligands for the synthesis of highly monodisperse and fluorescent gold nanoclusters (AuNCs). The xanthate in the PCIEs interacts with Au ions, acting as a well-controlled template for the direct formation of PCIE-AuNCs. This method yields red-emitting AuNCs with a narrow emission peak (λem = 645 nm), good quantum yield (4.3−4.8%), long fluorescence decay time (∼722−844 ns), and unprecedented product yield (>98%). The PCIE-AuNCs exhibit long-term colloidal stability, biocompatibility, and antifouling properties, enabling a prolonged blood circulation, lower nonspecific accumulation in major organs, and better renal clearance when compared with AuNCs without polymer coating. The advances made here in the synthesis of metal nanoclusters using xanthate-functionalized PCIEs could propel the production of highly monodisperse, biocompatible, and renally clearable nanoprobes in large-scale for different theranostic applications.

Original languageEnglish
Pages (from-to)476–484
Number of pages9
JournalNano Letters
Volume21
Issue number1
DOIs
Publication statusPublished - 2021

Keywords

  • Charge transfer
  • Fluorescence
  • Gold nanoclusters
  • Monodispersity
  • Poly(2-oxazoline)
  • Xanthate

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