【作者】 张慧； 邱玉琴； 刘敏； 陈晓； 严军； 吴叶宇； 杜方凯； 谭学才；

【Author】 Hui Zhang;Yuqin Qiu;Xiao Chen;Min Liu;Jun Yan;Yeyu Wu;Fangkai Du;Xuecai Tan;School of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Key Laboratory of Guangxi Colleges and Universities for Food Safety and Pharmaceutical Analytical Chemistry, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products;

【机构】 广西民族大学化学化工学院广西高校食品安全与药物分析化学重点实验室广西林产化学与工程重点实验室；

【摘要】 使用二氧化硅（SiO₂）与氮掺杂石墨烯（N-GQDs）（SiO₂@N-GQDs）的复合材料标记适配体来增强发光强度,成功构建了基于适配体置换的固态电化学发光（ECL）适体传感器,用于高度灵敏地检测凝血酶。通过修饰Pt纳米颗粒（PtNPs）和三联吡啶钌(Ru（bpy）₃²⁺)（Ru-PtNPs）复合物到3D石墨烯修饰电极的表面而制备ECL基底。由SiO₂@N-GQDs标记的凝血酶适体（Thrombin aptamer,TBA）作为ECL强度扩增。应用凝血酶适体以与互补性凝血酶适体（适体Ⅱ）杂交,在电极表面上产生适体Ⅱ-TBA的双链体复合物。凝血酶的引入触发了TBA从自组装双链体置换到溶液中和惰性蛋白凝血酶在电极表面上的缔合,减少了SiO₂@N-GQDs的量并增加了适体传感器的电子转移电阻,ECL信号大幅减少。通过SiO₂@N-GQDs对Ru（bpy）₃²⁺ECL的协同扩增,适体传感器在检测凝血酶之前和之后显示出较大的ECL强度变化。结果,ECL强度的变化与凝血酶浓度的对数在0.002-50nM的范围内具有直接关系。所提出的适体传感器的检测限为0.02pM。因此,该方法预期为临床以及生物分析中的蛋白质诊断提供了新的机会。更多还原

【Abstract】 A sensitive electrochemiluminescence（ECL） aptasensor was established on target-induced aptamer displacement for highly sensitive detection of Thrombin（TB） was developed successfully using Silica@ N-doped graphene quantum dots（SiO₂@N-GQDs） nanocomposites labeling as enhancer.The ECL substrate was made by modifying the complex of Pt nanoparticles（PtNPs） and tris（2,2-bipyridyl） ruthenium（Ⅱ）(Ru（bpy）₃²⁺)（Ru–PtNPs） onto nafion@3 D graphene modified electrode surface.The thrombin aptamer（TBA） labeled by SiO₂@N-GQDs acted as the ECL intensity amplification.The labeled thrombin aptamer was applied to hybridize with the complementary thrombin aptamer（Aptamer Ⅱ）, yielding a duplex complex of Aptamer Ⅱ–TBA on the electrode surface.The introduction of thrombin triggered the displacement of TBA from the self-assembled duplex into the solution and the association of inert protein thrombin on the electrode surface, decreasing the amount of SiO₂@ N-GQDs and increasing the electron transfer resistance of the aptasensor and thus resulting large decrease in ECL signal.With the synergistic amplification of SiO₂@N-GQDs to Ru（bpy）₃²⁺ECL, the aptasensor showed an enlarged ECL intensity change before and after the detection of thrombin.As a result, the change of ECL intensity has a direct relationship with the logarithm of thrombin concentration in the range of 0.002-50 nM.The detection limit of the proposed aptasensor is 0.02 pM.Thus, the approach is expected to open new opportunities for protein diagnostics in clinical as well as bioanalysis in general.更多还原