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Purification of Nano‐Porous Silicon for Biomedical Applications
Author(s) -
Koynov Svetoslav,
Pereira Rui N.,
Crnolatac Ivo,
Kovalev Dmitry,
Huygens Ann,
Chirvony Vladimir,
Stutzmann Martin,
de Witte Peter
Publication year - 2011
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201080091
Subject(s) - materials science , singlet oxygen , silicon , nanoporous , porous silicon , nanotechnology , impurity , biocompatibility , chemical engineering , fourier transform infrared spectroscopy , nanomaterials , photodynamic therapy , spectroscopy , isotropic etching , etching (microfabrication) , oxygen , optoelectronics , chemistry , organic chemistry , physics , quantum mechanics , engineering , metallurgy , layer (electronics)
Recently, various bio‐medical applications of nanoporous silicon (np‐Si) have been suggested. This work investigates the biocompatibility of np‐Si particles taking into account hazardous residua confined in the pores after preparation. The emphasis is on the potential application of such particles as oxygen photosensitizer for photodynamic therapy of cancer, which requires both negligible toxicity of np‐Si particles in darkness and a high photo‐cyto‐toxic effect due to generation of singlet oxygen under illumination. Considerable amounts of water soluble toxic impurities are found to be present in the nanoporous shell of micrometer‐sized np‐Si particles immediately after their preparation by chemical etching of bulk silicon powder. The effects of several ordinary cleaning treatments are investigated by using thermal effusion mass‐spectroscopy and FTIR spectroscopy. A particular purification procedure is developed, capable to reduce the concentration of residual impurities to levels acceptable for bio‐medical applications while preserving the required photo‐activity of the np‐Si particles.