Nucleic acid immobilized polypyrrole–polyvinylsulphonate film for Mycobacterium tuberculosis detection

21-mer peptide acid nucleic acid (PNA) probe specific to 16s–23s rRNA spacer region of Mycobacterium tuberculosis has been covalently immobilized on polypyrrole–polyvinylsulphonate film electro-chemically deposited onto indium-tin-oxide (ITO) glass for detection of complementary target by monitoring guanine oxidation and redox indicators (methylene blue and ruthenium complex) up to 0.1 fmole, 0.1 attomole and 1.0 pmole, respectively within 30 s of hybridization time. The peptide nucleic acid immobilized polypyrrole–polyvinylsulphonate electrode can be used for hybridization detection with complementary sequence in heat-shocked genomic DNA and in serum samples containing genomic M. tuberculosis DNA up to 2.5 pg/μl within about 60 min at 30 °C and can be used 8–9 times.