Water-Soluble Luminescent Silicon Nanocrystals by Plasma-Induced Acrylic Acid Grafting and PEGylation

Zhaohan Li, Advitiya Mahajan, Himashi Andaraarachchi, Yeonjoo Lee, Uwe R. Kortshagen

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


Luminescent silicon nanocrystals are promising nanomaterials for biomedical applications due to their unique optical properties and biocompatibility. Here, we demonstrate a two-step surface modification approach coupling gas-phase and liquid-phase methods to synthesize PEGylated acrylic acid grafted silicon nanocrystals with near-infrared emission in water and biological media. First, acrylic acid grafted silicon nanocrystals are synthesized by an all-gas-phase approach on a millisecond time scale, omitting high temperature and postpurification processes. Subsequently, room-temperature PEGylation is carried out with these acrylic acid grafted silicon nanocrystals, yielding stable colloidal dispersions in both water and high ionic strength Tyrode's buffer with 20-30 nm hydrodynamic diameters. The PEGylated silicon nanocrystals exhibit photoluminescence in the 650-900 nm near-IR window with quantum yields of ∼30% and ∼13% in deionized water and Tyrode's buffer, respectively, after a 7-day oxidation in water. The surface-functionalized Si NCs exhibit relatively small toxicity to MDA-MB-231 cells at concentrations relevant to bioimaging applications.

Original languageEnglish (US)
Pages (from-to)105-112
Number of pages8
JournalACS Applied Bio Materials
Issue number1
StatePublished - Dec 14 2021

Bibliographical note

Funding Information:
This work was supported by the National Institute of Health under Award R01DA045549. XRD, XPS, and TEM were carried out in the Characterization Facility, University of Minnesota, which receives partial support from NSF through the MRSEC program Award DMR-2011401. Portions of this work were conducted in the Minnesota Nano Center, which is supported by the National Science Foundation through the National Nano Coordinated Infrastructure (NNCI) Network under Award ECCS-2025124.

Publisher Copyright:
© 2021 American Chemical Society.


  • bioimaging
  • colloidal stability
  • photoluminescence
  • plasmas
  • quantum dots
  • silicon nanocrystals

MRSEC Support

  • Shared

PubMed: MeSH publication types

  • Journal Article
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, N.I.H., Extramural


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