基于富勒烯衍生物修饰玻碳电极的DNA电化学传感器

以富勒烯C₆₀, L-苏氨酸及对苯二甲醛为原料, 在氮气保护下反应得到含醛基官能团的2-(4-醛基苯基)-5-(1-羟乙基)富勒烯吡咯烷衍生物(C₆₀-CHO). 将该材料修饰于玻碳电极表面, 并利用醛基与氨基之间温和、高效的缩合反应, 将5-氨基修饰的寡聚核苷酸共价固定到了C₆₀-CHO修饰的玻碳电极表面, 构建了一种新型的电化学DNA传感器. 以[Fe(CN)₆]^3−/4−为电活性探针, 采用电化学阻抗法对转基因植物CaMV35S启动子基因特征片段进行检测. 实验结果表明, 杂交前后的电子传递电阻差值(DR_et)与目标序列浓度对数(lg C_S2)在1.0×10^－13～1.0×10^－9 mol/L浓度范围内呈良好的线性关系, 线性回归方程为DR_et/(10³ Ω)＝3.471 lg (C_S2/mol/L)＋50.425 (r＝0.9977), 检测限为1.5×10⁻¹⁴ mol/L. 杂交特异性实验进一步表明该传感器对完全互补、碱基错配和非互补序列具有良好的识别能力.     

Grafting of Acrylamide and Trimethylolpropane Triglycidyl Ether onto the Gellan Gum: Synthesis and Characterization

To improve the physiochemical properties of gellan gum(GG), GG was modified with acrylamide and trimethylolpropane triglycidyl ether(TTE). The structure and morphology of modified GG were characterized by Fourier transform infrared(FT-IR) spectroscopy, X-ray diffraction(XRD), differential scanning calorimetry(DSC) and scanning electron microscopy(SEM). The characteristic peaks at 3448, 2788, 1654, 1411, 1117 and 1044 cm~(-1) in the FT-IR spectrum confirm the modification. The XRD and DSC data revealed that the modification enhanced the thermal stability of GG. SEM analysis suggested the modification introduced a porous microstructure, resulting in the adsorption of crystal violet. In addition, the adsorption capacity, thermal stability and swelling property of GGTTE3 were superior to GGTTE1, GGTTE2, GGTTE4 and GGTTE5.