Experimental Study On Molecular Identification Using Various Nanopore Sensors

After decades of development,nanopore technology has made great progress in molecular detection.However,for the gene sequencing and precision treatment proposed by precision medicine,it is difficult for traditional nanopore technology to obtain enough molecular information.In this regard,this topic proposes two new types of nanopore sensing systems,using DNA molecules and protein molecules as detection media,and a combination of simulation and experiment methods in order to obtain more molecular information.The main contents of this study are as follows:(1)Based on the principle of molecular vias,an experimental platform for driving molecules and detection was established,and 20 nm?40 nm nanopores were successfully prepared using focused ion etching technology.The prepared nanopores are connected in series to build a series nanopore system.The dry and wet transfer methods were used to transfer the graphene material to the silicon nitride nanopores,and 40 nm nanopores were prepared on the graphene film using ion etching technology to complete the nanocage structure's preparation.(2)The traditional nano-sensors were used to collect and study the translocation of DNA molecules,and the effects of DNA concentration and applied voltage on the translocation events of DNA molecules were explored.The traditional nano-sensors were used to collect and study the translocation of protein molecules,and the appearance and size of proteins were more intuitively recognized through experiments.(3)The molecular information was collected by various nanosensors.A series nanopore system was used to study the structure of DNA molecules in detail.Explore the signal amplification effect of the tandem pore structure.Analyzing the voltage signal,further clarifying the specific folding pattern of the DNA molecule.Using the tandem pore structure to explore the difference between the molecular collision signal and the molecular translocation signal.The translocation of DNA molecules has been studied using nano-cage.Experimental results show that cage-like structures have a limiting effect on DNA and can increase the reverse capture rate of DNA molecules.(4)The fluid simulation was performed using Comsol software.The simulation of molecular vias in a single-hole structure simulates the electric field distribution and capture area under a single hole.Simulations of molecular translocation in a nano-cage structure are simulated.It does have a molecular capture effect.The nanopore with double-pore structure is simulated,so that the capture regions of the two nanopores overlap,which can be used for the length identification and screening of DNA molecules.