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The breakage and damage of plasmid DNA photocatalized by TiO 2 /carbon nanotube composites
Author(s) -
Li Song,
Xiong Xinhong,
Li Wenfeng
Publication year - 2012
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.3775
Subject(s) - carbon nanotube , breakage , dna , circular dichroism , molecule , dna damage , chemistry , plasmid , electrophoresis , gel electrophoresis , materials science , nanotechnology , composite material , crystallography , biochemistry , organic chemistry
In this paper, the plasmid DNA was used as a target to evaluate the bioeffect of TiO 2 /Carbon Nanotube (CNT) composites. The conformational change and breakage of DNA induced by the composites were characterized by the integrated tools of electrochemistry, circular dichroism (CD), atomic force microscopy (AFM), and DNA electrophoresis. At the early stage of incubation, the DNA double helix conformation was substantially changed by TiO 2 /CNT composites. Both electrophoresis and electrochemistry results suggested the breakage and damage appeared on the native DNA molecules. When DNA was treated longer by TiO 2 /CNT, DNA molecules were broken into fragment. AFM images confirmed the process. The DNA damage was deemed to be a gradual process: supercoiled plasmid DNA was first damaged to nicked‐circle structure, then further to linear form, and then DNA fragment. Copyright © 2011 John Wiley & Sons, Ltd.