▎ 摘　　要

8-Hydroxy-2'-deoxyguanosine (8-OH-dG) is the most abundant oxidative product of DNA and it is also considered to be a biomarker of oxidative DNA damage. In this work, a novel biosensor was fabricated by combining the biocompatibility of single stranded DNA (ss-DNA) and the excellent conductivity of graphene nanosheets (GNs). The biosensor showed high electrocatalytic activity to the oxidation of 8-OH-dG. The sensitivities were 13.23 (+/- 0.03) mu A mu M-1, 5.827 (+/-.008) mu A mu M-1 and 3.086 (+/- 0.005) mu A mu M-1 in the concentration ranges of 0.0056-1.155 mu M, 1.155-11.655 mu M and 11.655-36.155 mu M, respectively. The detection limit was 0.875 nM (S/N=3). Furthermore, the electrochemical behavior of 8-OH-dG was also investigated in detail in the presence of uric acid. And the results showed that uric acid had interference with the trace detection of 8-OH-dG. But it can be eliminated completely by uricase. The as-prepared ss-DNA/GNs/GCE will be promising for the detection of 8-OH-dG in real samples. (C) 2015 Elsevier B.V. All rights reserved.