Techniques, methods, devices, and compositions are disclosed that are useful in identifying and sequencing natural and synthetic, and modified and unmodified DNA, RNA, PNA, DNA/RNA nucleotides. The disclosed techniques, methods, devices, and compositions are useful in identifying various modifications, DNA/RNA damage, and nucleotide structure, using nanoelectronic quantum tunneling spectroscopy, which may be referred to as QM-Seq. The methods and compositions can include the use of a charged, smooth substrate for deposition of single stranded nucleotides and polynucleotide macromolecules, scanning the modified or unmodified DNA/RNA/PNA, comparing the electronic signatures of an unknown nucleobase against a database of electronic fingerprints of known nucleobases, including natural and synthetic, modified and unmodified nucleobases, and secondary/tertiary structure, obtained under the same or similar conditions, for example where the nucleobase is in an acidic environment.