Figure 4. Apply of composite of material.

The 3D DNA nanostructure stable at Au surface is monitored in real-time using QCM. HS-3D DNA nanostructure is synthesized by 3 thiol modified oligonucleotides and 1 none modified oligonucleotide. After HS-3D DNA anchoring at Au surface, the 3 thiol modified oligonucleotides which are anchoring at Au surfaces by Au-S chemical bond can't be washed out of the Au surface by DI water. However, the 1 none modified oligonucleotide could be washed out of the Au surface by DI water. So there is about 25% frequency increase. When HS-3D DNA which is layered at Au surface (black line) is washed by DI water, the increase of frequency is about 30 Hz in 300 minutes (blue space). The frequency signal change is about 25% relative to 120 Hz, which indicates that HS-3D DNA nanostructure is disassembled. However, addition of M₆L₄ sphere frameworks and forming a new composite material is washed by DI water, the frequency keeps almost constant (red line), which suggests that HS-3D DNA nanostructure is stable. The data shows that this new composite material can keep 3D DNA nanostructure more stable than only 3D DNA nanostructure in DI water. All the experiments are carried out at room temperature.