Hierarchical Nanostructuring of Porous Silicon with Electrochemical and Regenerative Electroless Etching.
Ermei MäkiläAnne-Mari Anton WillmoreHaibo YuMarianna IrriMark AindowTambet TeesaluLeigh T CanhamKurt W KolasinskiJarno SalonenPublished in: ACS nano (2019)
Hierarchically nanostructured silicon was produced by regenerative electroless etching (ReEtching) of Si powder made from pulverized anodized porous silicon. This material is characterized by ∼15 nm mesopores, into the walls of which tortuous 2-4 nm pores have been introduced. The walls are sufficiently narrow that they support quantum-confined crystallites that are photoluminescent. With suitable parameters, the ReEtching process also provides control over the emission color of the photoluminescence. Ball milling and hydrosilylation of this powder with undecylenic acid produces nanoparticles with hydrodynamic diameter of ∼220 nm that exhibit robust and bright luminescence that can be excited with either one ultraviolet/visible photon or two near-infrared photons. The long-lived, robust visible photoluminescence of these chemically passivated porous silicon nanoparticles is well-suited for bioimaging and theranostic applications.
Keyphrases
- light emitting
- quantum dots
- energy transfer
- tissue engineering
- photodynamic therapy
- stem cells
- mesenchymal stem cells
- metal organic framework
- cell therapy
- gold nanoparticles
- living cells
- molecular dynamics
- highly efficient
- fluorescence imaging
- room temperature
- ionic liquid
- mass spectrometry
- walled carbon nanotubes
- fluorescent probe