Targeted optical injection of gold nanoparticles into single mammalian cells

We present an all optical technique for the targeted delivery of single 100 nm diameter gold nanoparticles into a specified region of the interior of an individual mammalian cell through a combination of optical tweezing and optical injection. The internalisation of the nanoparticle is verified by confocal laser scanning microscopy and confocal laser scanning reflectance microscopy. This represents the first time that nano sized particles have been tweezed and optically injected into mammalian cells using only light, and provides a novel methodology for internalising nanosphere based biosensors within specific intracellular regions of a mammalian cell. Confocal cross sections in xy (main), xz (bottom) and yz (right) of a Chinese hamster ovary cell (green) containing an optically injected 100 nm gold nanoparticle (red) within the nucleus. [GRAPHICS] (C) 2009 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim