Department of Chemistry and Environment Science, Fujian Province University Key Laboratory of Analytical Science, Zhangzhou Normal University, Zhangzhou 363000, PR China.
Mater Sci Eng C Mater Biol Appl. 2013 Oct;33(7):3851-7. doi: 10.1016/j.msec.2013.05.022. Epub 2013 May 18.
A stable and uniform organic-inorganic nanocomposite that consists of graphene (GR) and pyrenebutyric acid (PBA) was obtained by ultrasonication, which was characterized by scanning electron microscopy (SEM) and UV-vis absorption spectra. The dispersion was dropped onto a gold electrode surface to obtain GR-PBA modified electrode (GR-PBA/Au). Electrochemical behaviors of the modified electrode were characterized by cyclic voltammetry and electrochemical impedance spectroscopy using Fe(CN)6 as the electroactive probe. A novel DNA biosensor was constructed based on the covalent coupling of amino modified oligonucleotides with the carboxylic group on PBA. By using methylene blue (MB) as a redox-active hybridization indicator, the biosensor was applied to electrochemically detect the complementary sequence, and the results suggested that the peak currents of MB showed a good linear relationship with the logarithm values of target DNA concentrations in the range from 1.0×10(-15) to 5.0×10(-12) M with a detection limit of 3.8×10(-16) M. The selectivity experiment also showed that the biosensor can well distinguish the target DNA from the non-complementary sequences.
通过超声处理得到了由石墨烯（GR）和芘丁酸（PBA）组成的稳定且均匀的有机-无机纳米复合材料，其通过扫描电子显微镜（SEM）和紫外-可见吸收光谱进行了表征。将分散体滴到金电极表面上，得到 GR-PBA 修饰电极（GR-PBA/Au）。通过循环伏安法和电化学阻抗谱，以 Fe(CN)6 作为电活性探针，对修饰电极的电化学行为进行了表征。基于氨基修饰的寡核苷酸与 PBA 上的羧基的共价偶联，构建了一种新型的 DNA 生物传感器。通过使用亚甲基蓝（MB）作为氧化还原活性杂交指示剂，该生物传感器被用于电化学检测互补序列，结果表明，MB 的峰电流与目标 DNA 浓度的对数在 1.0×10(-15) 到 5.0×10(-12) M 的范围内呈良好的线性关系，检测限为 3.8×10(-16) M。选择性实验还表明，该生物传感器可以很好地区分目标 DNA 与非互补序列。
