To understand and improve the translocation dynamics of nanopore based sensors, we studied theoretically the translocation of DNA molecules and compared them with experimental results. In our experimental studies, we used conically shaped track-etched polymer (i.e., PET) membrane and built our model based on its physical properties. Simulations were conducted by varying the surface charges of the nanopore and the particle, particle (i.e., DNA) position and applied potential to examine the translocational behavior of DNA and its effect on current-pulse shape. Our results showed that variations in surface and DNA charge density cause conductive distortions indicating the interaction between the surface and the DNA. It also confirmed that the DNA charge density does not remain in its native form in the solution as well as the pore charge during the translocation.