Provided is a method of sensitively detecting nucleic acids in a nucleic acid sample, the method comprising: contacting the sample comprising the nucleic acid with a non-specific nucleic acid binding agent in an electrically conductive fluid medium; contacting the sample comprising the nucleic acid bound to the agent with a nanopore; and applying a voltage to the nanopore and monitoring a current change through the nanopore. The nucleic acid can be sensitively detected because a change in current amplitude through the nanopore is greater than when nucleic aid detection is performed without using an intercalator.