Au nanoparticle-DNAzyme dual catalyst system for sensitively colorimetric detection of thrombin

作者：Rao Xin yi; Zhang Jia jia; Cui Jing; Hu Ying; Liu Ting; Chai Jing feng; Cheng Gui fang^*; He Pin gang; Fang Yu zhi

来源：Chemical Research in Chinese Universities, 2013, 29(5): 868-873.

DOI：10.1007/s40242-013-3039-1

• Au nanoparticle
• Magnetic nanoparticle
• DNAzyme
• Aptamer
• Thrombin

A novel colorimetric aptasensor was developed for thrombin detection with high sensitivity and specificity. The assay takes the advantage of Au nanoparticles-DNAzyme as a dual catalytic system for signal amplification. Au nanparticles were modified with peroxidase mimicking DNAzyme sequence as well as thrombin binding aptamer. And then the thrombin binding aptamer hybridized with its complementary sequence which was immobilized on the surface of the magnetic nanoparticles to construct the colorimetric aptasensor. In the presence of thrombin, the target-induced displacement takes place, resulting in the dissociation of the aptasensor. The DNAzyme functioned Au NPs are released due to the combine ability of thrombin binding aptamer with thrombin. The released Au NPs are capable of catalyzing the colorless 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid(ABTS) conversion into a blue-green product by H2O2-mediated oxidation, thus can amplify the colorimetric readout signals of thrombin detection. Such a device can serve as a novel selectivity sensor for thrombin with a detection limit of 0.6 nmol/L.

• 出版日期2013-10
• 单位华东师范大学