title: A sandwich-type DNA biosensor based on electrochemical co-reduction synthesis of graphene-three dimensional nanostructure gold nanocomposite films.
abstract: A novel electrochemical DNA biosensor based on graphene-three dimensional nanostructure gold nanocomposite modified glassy carbon electrode (G-3D Au/GCE) was fabricated for detection of survivin gene which was correlated with osteosarcoma. The G-3D Au film was prepared with one-step electrochemical coreduction with graphite oxide and HAuCl4 at cathodic potentials. The active surface area of G-3D Au/GCE was 2.629cm(2), which was about 3.8 times compared to that of a Au-coated GCE under the same experimental conditions, and 8.8 times compared to a planar gold electrode with a similar geometric area. The resultant nanocomposites with high conductivity, electrocatalysis and biocompatibility were characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). A "sandwich-type" detection strategy was employed in this electrochemical DNA biosensor and the response of this DNA biosensor was measured by CV and amperometric current-time curve detection. Under optimum conditions, there was a good linear relationship between the current signal and the logarithmic function of complementary DNA concentration in a range of 50-5000fM with a detection limit of 3.4fM. This new biosensor exhibited a fast amperometric response, high sensitivity and selectivity and has been used in a polymerase chain reaction assay of real-life sample with a satisfactory result.
authors: Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350004, PR China.
authors: Ai-Lin
authors: AL
authors: Liu
authors: Guang-Xian
authors: GX
authors: Zhong
authors: Jin-Yuan
authors: JY
authors: Chen
authors: Shao-Huang
authors: SH
authors: Weng
authors: Hong-Nan
authors: HN
authors: Huang
authors: Wei
authors: W
authors: Chen
authors: Li-Qing
authors: LQ
authors: Lin
authors: Yun
authors: Y
authors: Lei
authors: Fei-Huan
authors: FH
authors: Fu
authors: Zhou-liang
authors: ZL
authors: Sun
authors: Xin-Hua
authors: XH
authors: Lin
authors: Jian-Hua
authors: JH
authors: Lin
authors: Shu-Yu
authors: SY
authors: Yang
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000032:analysis*; D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D012516:Osteosarcoma / Q000235:genetics*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry
chemical_list: D010087:Oxides; D006046:Gold; D006108:Graphite; D004247:DNA