Embodiments disclosed herein relate to a method of detecting specific DNA sequences and the application of this method in the detection of pathogens, viruses, drug-resistant pathogens, genomic variations associated with disease/disorder susceptibility etc. based on specific signature sequences unique to the pathogens, viruses, drug-resistant pathogens or genomic variations. The method can also be used to distinguish a pool of same-sized dsDNA on the basis of sequence differences. The method uses non-optically labeled bis-PNA and/or gamma-PNA probes to tag specific target sequences for identification by solid-state nanopores.