www.afm-journal.de FULL PAPER © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Adv. Funct. Mater. 2010, 20, 3136–3142 3136 www.MaterialsViews.com wileyonlinelibrary.com DOI: 10.1002/adfm.201000846 By Alexey M. Yashchenok, Daniil N. Bratashov, Dmitry A. Gorin,* Maria V. Lomova, Anton M. Pavlov, Andrei V. Sapelkin, Bong Sup Shim, Gennady B. Khomutov, Nicholas A. Kotov, Gleb B. Sukhorukov, Helmuth Möhwald, and Andre G. Skirtach 1. Introduction Since their discovery by Iijima in 1991 carbon nanotubes are becoming one of the most promising types of materials for nanotechnology. [1,2] They show great promise as materials of choice for surface functionalization enhancing mechanical properties of materials, [3–10] nanoelectronics, [11,12] catalysis, [13–15] diagnostics [16,17] and drug delivery. [18–19] Exceptional mechanical and optical properties of carbon nanotubes make them attrac- tive candidates as functional blocks in molecular assemblies. Incorporation of carbon nanotubes into supramolecular struc- tures is also of great interest to a broad field of nanostructured materials. [20] Recently nano-engineered multilayer structures incorporating carbon nanotubes have been also fabricated by the layer-by-layer self-assembly (LbL). [8–10] This led to fabrication of multifunctional nano-structured polymeric materials with tunable properties. [21,22] The LbL assembly is based on the sequential adsorption of charged species onto oppositely charged surfaces. By con- secutive adsorption steps one is able to build multilayers based on electrostatic interactions. LbL coating of a sacrificial colloidal template can be followed by the dissolution of the template thus producing hollow polyelectrolyte capsules. [23,24] Due to the modularity of the LbL technique it is possible to fabricate tailor-made cap- sules with multifunctional [25] or stimuli responsive [26,27] walls which can be used in drug-delivery applications. [28,29] Recently the remote activation of microcapsules containing noble metal nanoparticles has been demonstrated. [25–31] To-date, numerous studies focused on microcapsules containing gold nanoparti- cles. [27–29] Remote release and polyelectrolyte multilayer capsule permeability control due to laser-nanoparticle interaction leads to release of encapsulated materials, and this can be performed inside living cells. This method has already been demonstrated as an important tool in molecular biology. [28–30] For example, we have shown [30] that signal peptides intracellularly released by near-IR irradiation, [31] are bound to the major histocompat- ibility complex (MHC) Class I molecules and transported to the surface of cells. The complex presentation on the cell surface Carbon Nanotubes on Polymeric Microcapsules: Free- Standing Structures and Point-Wise Laser Openings Single-wall carbon nanotubes modified by anionic polyelectrolyte molecules are embedded into the shells of microcapsules. Carbon nanotubes serve as rigid rods in a softer polymeric capsule, which forms a free-standing shell upon treat- ment with glutaraldehyde and subsequent drying. The embedded carbon nano- tubes exhibit a broad absorption in the UV–near-infrared part of the spectrum, and that allows point-wise activation and opening of the microcapsules by laser. Raman signal analysis shows changes of carbon-nanotube-specific lines after high-power laser irradiation, which is characteristic of the formation of disordered carbonlike structures. These polyelectrolyte/carbon nanotube com- posite capsules represent a novel light-addressable type of microcontainers. [∗] Dr. A. M. Yashchenok, D. N. Bratashov, Dr. D. A. Gorin, M. V. Lomova, A. M. Pavlov Faculty of Nano- and Biomedical Technologies Saratov State University Saratov, 410012 (Russia) E-mail: gorin@mpikg.mpg.de Dr. D. A. Gorin Department of Interfaces Max-Planck Institute of Colloids and Interfaces Golm/Potsdam, D14476 (Germany) A. M. Pavlov, Prof. G. B. Sukhorukov School of Engineering & Materials Science Queen Mary University of London Mile End Road, London, E1 4NS (UK) Dr. A. V. Sapelkin Department of Physics, Queen Mary University of London Mile End Road, London, E1 4NS (UK) B.S. Shim, Prof. N. A. Kotov Department of Chemistry, University of Michigan Ann Arbor, MI 48109 (USA) Prof. G. B. Khomutov Faculty of Physics, Moscow State University Moscow, 119899 (Russia) Prof. G. B. Khomutov Institute of Nanotechnologies for Microelectronics Leninsky Pr. 32a, Moscow 119991 (Russia) Prof. H. Möhwald, Dr. A. G. Skirtach Department of Interfaces Max-Planck Institute of Colloids and Interfaces Golm/Potsdam, D14476 (Germany)