Carbon nanowalls (CNWs) are functionalized with short DNA strands. CNWs are a network of upstanding carbon flakes consisting of 4-6 graphene layers packed together. The biological modi. cation of these structures is carried out via the photochemical attachment of an unsaturated fatty acid linker molecule, followed by an EDC-mediated reaction to bind amino-modified DNA strands to the linker. Hybridization experiments are done using complementary and mismatch DNA strands. Fluorescence microscopy shows a clear difference between EDC-negative and EDC-positive samples, supporting the covalent nature of the DNA attachment. Furthermore, we demonstrate that the hybridization is highly selective and reproducible. (C) 2009 Elsevier B. V. All rights reserved.