Sensing with nanostructures is quoted as one of the most sensitive bioanalytical method as in many cases it enabled the molecular control of the detection process and the remarkably high, sometimes single-molecule level sensitivity. Because they possess the same potential, chemically modified nanopores are a notable target of cutting-edge research in nanotechnology and life sciences. In the field of analytics its application has three important trend: (a) ultrafast DNA sequencing (determining the base pair order in the DNA strand); (b) biosensing with selective receptor modified nanopores; (c) macromolecule and nanoparticle counting. Even though the sensing method is similar to Coulter-counting (which uses micron-scale slits), shrinking the sensor to the nano-scale results in the emergence of novel effects. Therefore, it is of key importance for conscious development to know that how species with different physical and chemical properties modulate the current and how can we influence their translocation frequency.
During my work I investigated the current-response of a nanopore during nanoparticle translocation for various experimental parameters through experiments and numerical simulations. The simulations were based on the Poisson, Nernst-Planck and Navier-Stokes differential equations, which I carried out with the COMSOL Multiphysics finite element package. The purpose of my work was to find parameters, which are able to improve the sensitivity of the nanopore, to understand the sensing mechanism, and provide the undisturbed translocation of the analytes hereby forming basis for single-nanopore sensor development aimed at virus and nanoparticle counting.