Meanwhile,the functionalized 1pDNA-AuNP-bDNA-NTs complex was centrifuged at 13,000rpm for 20 min and the unreacted thiolated oligonucleotides in the supernatant were removed.
The purified 1pDNA-AuNP-bDNA-NTs complex was resuspended in 200L assay buffer, and 40L was then added into 200L solution containing the MNP-2pDNA/tDNA.
The hybridization was incubated at 45 ◦C for 1 h with shaking. After the sandwich structure (MNP-2pDNA/tDNA/1pDNA-AuNP-bDNA-NTs) was formed, the solution was put on the magnetic separator for 3min and then the supernatant was removed.