Probes Design Of DNA Nanostructure At The CNTs Interface And Space Arrangement

The precise control of nanomaterials can make good use of its self-assembly performance and realize the construction of nanodevices,leading the development of new materials and their wide application in biomedical fields.As a carrier of genetic information,DNA stores a large amount of information,and it can realize the transmission of information through base pairing,as well as the regulation of the position,distance,structure,and performance of nanomaterials.Firstly,this research discusses the interaction mechanism based on the specificity and addressability of DNA sequences between different sequences and carbon nanotube materials,and realizes the direct visual detection of DNA sequences,which providing a new method of information storage.Based on the construction of DNA-carbon nanotube probes,a series of accurate and effective carbon nanotube arrays were constructed through the precise positioning ability of DNA nanostructures and the high hybridization ability of spherical nucleic acids.The details are as follows:(1)We developed a solid DNA self-assemble nano raft with a high degree of resistance to deformation and studied its physical properties.We modified the number of DNA bases in origami to improve its flatness,and increased its rigidity by increasing the thickness.Therefore,we constructed a type of DNA double-layer origami with controllable morphology,precise assembly,and high resistance.Compared with conventional single-layer DNA origami,the double-layer raft showed higher deformation resistance capability with the nano rafts possessing higher structural integrity.Using the deformation-resistant DNA self-assemble nano raft,we achieved the precise positioning of single-stranded DNA probes on the DNA nano interface by visualizing the AuNPs captured by the probes.Compared with the interface constructed by single-layer DNA origami,the distance between AuNPs on the double-layer DNA origami was more approximate to the theoretical value that we designed.This research provides a better support platform for the design and assembly of nanoparticles with controlled spacing and position.(2)We constructed gold nanoparticle arrays with different configurations on the rigid DNA origami.We further modified the design of structure to enhance the rigidity and flatness of origami,then we located gold nanoparticles by DNA hybridization on the interface to achieve the assembly of different configuration.We also constructed a large-scale rigid and flat origami template by using DNA sticky-end interaction and end-stacking forces,and realized the ordered assembly of nanoparticles at the interface.This provides support for efficient,limited-area reactions of small molecules,proteins,and macromolecular polymers.(3)we provided a spherical nucleic acids(SNAs)-mediated approach for highly precise and highly efficiency aligning CNTs at prescribed sites on DNA origami.Using the precise positioning ability of DNA origami and the high hybridization ability of spherical nucleic acids,a new type of SNAs-mediated carbon nanotubes arranged in parallel at the interface was developed.This method can control the accuracy of the array angle within 10 °.Compared with the traditional complementary pairing scheme,the assembly efficiency was improved by 5 times.In addition,by adjusting the shape of the interface arrangement,it has been proved that parallel-arranged carbon nanotubes can produce fewer conductive path errors than cross-linked arrangements.This combination approach of DNA nanotechnology and spherical nucleic acids presented great potential in manufacturing of high-performance electronic devices.(4)We developed a tubular nucleic acid by condensing DNA strands on the surface of carbon nanotubes.We found that there was a sequence-dependent specific interaction between DNA and carbon nanotubes.By deeply studying the interaction mechanism between DNA sequences and carbon nanotube interfaces,we had developed a series of DNA-carbon nanotube composite biological probes.Then through the highresolution imaging analysis of atomic force microscope,a visual direct reading detection of the DNA sequence was realized.Finally,a new method of DNA information storage based on the manipulation of carbon nanotubes was developed using the interaction between DNA and carbon nanotubes.