Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Enzymatic Digestion of Single DNA Molecules Anchored on Nanogold-Modiﬁed Surfaces | Nanoscale Res Lett 2009 4 1029-1034 DOI s11671-009-9350-6 NANO EXPRESS Enzymatic Digestion of Single DNA Molecules Anchored on Nanogold-Modified Surfaces Junhong Lu Ming Ye Na Duan Bin Li Received 9 January 2009 Accepted 14 May 2009 Published online 31 May 2009 to the authors 2009 Abstract To study enzyme-DNA interactions at single molecular level both the attachment points and the immediate surroundings of surfaces must be carefully considered such that they do not compromise the structural information and biological properties of the sample under investigation. The present work demonstrates the feasibility of enzymatic digestion of single DNA molecules attached to nanoparticle-modified surfaces. With Nanogold linking DNA to the mica surface by electrostatic interactions advantageous conditions with fewer effects on the length and topography of DNA are obtained and an appropriate environment for the activities of DNA is created. We demonstrate that by using Dip-Pen Nanolithography individual DNA molecules attached to modified mica surfaces can be efficiently digested by DNase I. Keywords Gold nanoparticles Mica DNA Atomic force microscopy Dip-Pen Nanolithography Introduction Advances in single-molecule techniques make it possible to explore new phenomena and unravel novel mechanisms in biology that were largely inaccessible by traditional bulk measurements 1 . For example studies of DNA-protein interaction at single molecular level could characterize the Electronic supplementary material The online version of this article doi s11671-009-9350-6 contains supplementary material which is available to authorized users. J. Lu M. Ye N. Duan B. Li H Shanghai Institute of Applied Physics Chinese Academy of Sciences . Box 800-204 Shanghai 201800 China e-mail libin@ distributions of molecular properties and observe the temporal evolution of complicated reaction pathways 2 . It is generally understood that single-molecule measurements require .