| 초록 |
Herein, we describe the label-free colorimetric assay based on EXPAR (exponential amplification reaction) utilizing ssDNA-AuNP adsorption complex for nucleic acid detection. In the assay, ssDNA-AuNP adsorption complex is formed due to the electrostatic interaction between target complementary ssDNA and citrated AuNP. When the ssDNA is adsorbed to AuNP, the adsorption complex can prevent aggregation even in the salt condition. However, in the presence of target DNA, target DNA can hybridize to adsorbed ssDNA, produce the extended dsDNA and amplifying probes catalyzed by DNA polymerase and nicking enzyme. Produced dsDNA departs from the AuNP, which can cause a color change from red to blue due to salt-induced aggregation. After then, amplified probes caused by EXPAR can act as target DNA again. This detection method is simple, rapid, sensitive, and easy to use at the on-site condition. Thus, it has great potential to apply the portable point-of-care device for nucleic acid detection. |
