An electrolytic system includes an analyte chamber having an access port for introducing a sample containing a molecules of interest, such as DNA. Electrodes create an electric field along a length of the analyte chamber to drive molecules toward an interaction region containing a nanopore, thereby increasing the arrival rate of molecules at the nanopore. Additional electrodes may be utilized to create an electric field through the nanopore to drive a molecule into the nanopore. A current sensor may be utilized to count, discriminate or characterize the molecules as they interact with the nanopore. Advantageously, system can be utilized for unamplified DNA sequencing.