Open Access Nano Express

Enhanced photoluminescence of porous silicon nanoparticles coated by bioresorbable polymers

Maxim B Gongalsky1, Alexander Yu Kharin1, Liubov A Osminkina1, Victor Yu Timoshenko1*, Jinyoung Jeong23, Han Lee23 and Bong Hyun Chung23

Author affiliations

1 Physics Department, Lomonosov Moscow State University, Leninskie Gory 1, Moscow, 119991, Russia

2 Major in Nanobioengineering, University of Science and Technology, Daejeon, 305-806, South Korea

3 BioNanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahangno Yuseong, Daejeon, 305-806, South Korea

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Citation and License

Nanoscale Research Letters 2012, 7:446  doi:10.1186/1556-276X-7-446

Published: 8 August 2012

Abstract

A significant enhancement of the photoluminescence (PL) efficiency is observed for aqueous suspensions of porous silicon nanoparticles (PSiNPs) coated by bioresorbable polymers, i.e., polylactic-co-glycolic acid (PLGA) and polyvinyl alcohol (PVA). PSiNPs with average size about 100 nm prepared by mechanical grinding of electrochemically etched porous silicon were dispersed in water to prepare the stable suspension. The inner hydrophobic PLGA layer prevents the PSiNPs from the dissolution in water, while the outer PVA layer makes the PSiNPs hydrophilic. The PL quantum yield of PLGA/PVA-coated PSiNPs was found to increase by three times for 2 weeks of the storage in water. The observed effect is explained by taking into account both suppression of the dissolution of PSiNPs in water and a process of the passivation of nonradiative defects in PSiNPs. The obtained results are interesting in view of the potential applications of PSiNPs in bioimaging.

Keywords:
Silicon nanoparticles; Porous silicon; Bioimaging; Polymer coating; Photoluminescence