Simulation Studies Of Nanoparticles Translocation Under A Solid-state Nanopore

Due to the potential advantages of sensitive, rapid, simple and inexpensive sensing devices, nanopore single molecule detection technology has a great potential for application in sequencing and nanoparticles or biomolecules detection. Presently, the detection of specific nanoparticles and bio-macromolecules has caused more and more attention. Based on electrophoretis force driven, charged nanoparticles will translocate through nanopore and ion current change occurs simultaneously. Those current changes contain various physicochemical properties and motion features of nanoparticles.The thesis is mainly about the preliminary study of magnetic nanoparticles detecting through a solid-state nanopore; presenting a simple simulation model to describe the motion behavior of nanoparticles; simulation about electro-osmotic flow characteristics and changing in and outside nanopore; simulation about the dynamic changes of rich rod-shaped nanoparticles with various dynamic behaviors of induced current changes. It is very important to improve the detection effect of nanopore sensor, the main results are as follows:DMSA modified Fe3O4 nanoparticles have been detected through chemical modified silicon nitride nanopore. Results and advantages of this method are analyzed and discussed. A simplified model has been presented, which can qualitatively describe the motion of nanoparticles in or outside nanopore.The PNP model simulation is used to study the morphology and variation of electro-osmotic flow inside and outside nanopore. The mechanism of these changes has been analyzed, the influence factors on electroosmotic flow have been discussed, the advantages and causing conditions about the flat electro-osmotic flow have been summarized.Using PB model, the dynamic changes of rod-shaped nanoparticles induced current changes are simulated and analyzed, mainly including the induced current changes under the changes of nanoparticles inside and outside nanopore and the complete translocation process dynamic changes. Then, analyses and discusses have been made contrast to the translocation singles under similarity translocation experiments, the validity of the results is successful.