摘要
介绍了一种利用互补核酸杂交富集金胶实现信号扩增的蛋白质生物传感器.以凝血酶蛋白为研究对象,利用凝血酶蛋白相对应的两段核酸适配体,将适配体Ⅰ固定在磁性颗粒上,用于特异性地捕获蛋白,将适配体Ⅱ标记金胶作为检测信标.由凝血酶蛋白和相对应的两段核酸适配体构建三明治结构的凝血酶蛋白生物传感器.另外,再通过信标金胶上过剩的核酸适配体链与另一段标记有金胶的互补核酸进一步杂交,获得金胶的选择性聚集,实现了信号扩增.通过信号扩增,使此传感器的灵敏度大大提高,对凝血酶蛋白的检测下限可达到4.52×10-15mol/L.平行测定浓度为7.47×10-14mol/L的凝血酶8次,其RSD为3.0%.该生物传感器对凝血酶蛋白有很好的特异性,其它蛋白如溶菌酶和牛血清白蛋白的存在对于检测没有影响.
In this paper, a signal amplified electrochemical biosensor for thrombin based on the enrichment of the gold nanoparticles through the hybridization with the complememtary oligonucleotide was presented. Thrombin, as a typical protein model, has two combination sites with aptamers. In the experiment, aptamer I was immobilized on magnetic nanoparticles for capturing thrombin, and aptamer 11 was labeled with gold nanoparticle to offer an excellent electrochemical signal transduction. Through the specific recognition for thrombin, a sandwich format of magnetic nanoparticle/thrombin/gold nanoparticle was fabricated. And the signal amplification was further implemented by the enrichment of gold nanoparticles through the hybridization with the gold labeled complementary oligonucleotide, the resulting hybridization is capable of realizing more gold nanoparticle markers attaching to each target protein. A significant enhancement of the sensitivity was obtained for the detection of thrombin with the signal amplification. This new strategy allows the detection limit of the target protein down to 4.52×10^-15mol/L. The relative standard deviation of eight replicate determinations of 7.47×10^-14mol/L thrombin was 3.0%. The presence of other proteins such as BSA and lysozyme did not affect the detection of thrombin, which indicates that a high specificity of thrombin detection can be achieved.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第12期2274-2279,共6页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:20675031)
上海市科委浦江人才计划(批准号:06PJ14032)资助
关键词
信号扩增
核酸适配体
凝血酶蛋白
金胶
电化学生物传感器
Signal amplification
Nucleic acid aptamer
Thrombin
Gold nanoparticle
Electrochemical biosensor
