Sung Tae Kim^†§, Dong-Joo Kim^‡§, Tae-Jin Kim^†, Deok-Won Seo^‡, Tae-Hong Kim^‡, Seung-Yong Lee^‡, Kwanghee Kim^†, Kyung-Mi Lee^*† and Sang-Kwon Lee^*‡

^† Global Research Laboratory, Department of Biochemistry, Division of Brain Korea, College of Medicine, Korea University, Seoul 136-701, Korea
^‡ Department of Semiconductor Science and Technology, Chonbuk National University, Jeonju 561-756, Korea

* To whom correspondence should be addressed. (S.-K.L.) Tel: +82-63-270-3973. Fax: +82-63-270-3585. (K.-M.L.) Tel: +82-2-920-6251. Fax: +82-2-920-6252., § These authors contributed equally to this study.

Abstract
Silicon nanowires (SiNWs) offer promising inorganic nanostructures for biomedical application. Here, we report the development of a novel SiNW array designed for isolating primary CD4⁺ T lymphocytes from the heterogeneous mixture of cell populations. Our system employed the specific high-affinity binding features of streptavidin (STR)-functionalized SiNW with biotin-labeled CD4⁺ T lymphocytes. Fabricated SiNW arrays easily separated the CD4⁺ T lymphocytes from the mouse whole splenocytes with over _~88% purity and demonstrated tight attachment to CD4⁺ T lymphocytes by scanning electron microscopy. Thus, our STR-SiNW arrays provide a potential tool for specific cell separation and further present a possibility to be applied to the other area of biomedical applications.

Keywords:Silicon nanowire; streptavidin; CD4⁺ T lymphocyte; cell separation