Controllable Preparation And Application Of Two-Dimensional Nanopores

Nanopore is attractive for its special applications in DNAsequencing. Compared with biological nanopores, solid-nanoporespresents obvious advantages such as very high stability, controllablediameter and channel length, adjustable surface properties and thepotential for intergration into devices and arrays. In this dissertation, wehave developed several methods to fabricate graphene nanopores andsingle-wall carbon nanotubes nanopores. We also carried out thetranslocations of λ-DNA and dNMPs through the nanopores. The electricsingle of dNMPs and λ-DNA with different forms had been recorded,leading a step toward single-molecule DNA sequencing.(1) Ecthing the metal substrate and transeferring the single-layergraphene to the given substrate, including SiO2/Si substrate, coppernetwork, Si3N4substrate with single pore, Si3N4substrate with pore array.Identifying the morphologies and structures of the pores by atomic forcemicroscope, scanning electron microscope and Raman specrometer, Thetransfered graphene was found to be single-layer, clean, and crackless.(2) Drilling a nanopore on the graphene transferring them to thegiven substrate by a series of methods, including chemical etchingmethod, electron beam method, current burning method. The diameter ofthe nanopores made by using the chemical ething method ranked from3 to7nm. The diameter of nanopores created by using the highly focusedelectron beam of a transmission electron microscope was over10nm.The diameter of nanopores fabricated by using current burning methodwas about10nm which is usually depending on the size of the probe. Wealso demonstrated the the diameter of the pore can be further shrinkedafter re-growth by CVD. The translocations of λ-DNA drivenelectrophoretically through the nanopore was performed and threecharacteristic signal were observed.(3)The growth and growth mechanism of superlong SWNTsoriented by gas flow were investigated. Both “Tip-growth” and“Base-growth” were experimentally proved. It was found that thenanotubes flying could travel across obstacle of hundreds micrometer anda slit in width of centimter-level. The transfered single surperlong SWNTto the polymer could be embeded and further cut into single-poremembrance, which could be used for single pore device for DNAsequencing. Nucleotides’ signal was detected by the device.