title: Polyaniline based nucleic acid sensor.
abstract: Twenty-bases long NH2-modified DNA and PNA probes specific to a pathogen (Mycobacterium tuberculosis) were covalently immobilized onto a polyaniline (PANI)/Au electrode to detect nucleic acid hybridization with complementary, one-base mismatch and noncomplementary targets within 30 s using Methylene Blue. The PNA-PANI/Au electrode exhibits improved specificity (1000 times) and detection limit (0.125 x 10(-18) M) as compared to that of the DNA-PANI/Au electrode (2.5 x 10(-18) M). These PNA-PANI/Au electrodes can be utilized for detection of hybridization with the complementary sequence in 5 min sonicated M. tuberculosis genomic DNA within 1 min of hybridization time. These DNA-PANI/Au and PNA-PANI/Au electrodes can be used 6-7 and 13-15 times, respectively.
authors.affiliation: Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr. KS Krishnan Marg, New Delhi-110012, India.
authors.forename: Nirmal
authors.initials: N
authors.lastname: Prabhakar
authors.forename: Kavita
authors.initials: K
authors.lastname: Arora
authors.forename: Harpal
authors.initials: H
authors.lastname: Singh
authors.forename: Bansi D
authors.initials: BD
authors.lastname: Malhotra
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004247:DNA / Q000032:analysis* / Q000235:genetics; D004563:Electrochemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D008751:Methylene Blue / Q000737:chemistry; D008855:Microscopy, Electron, Scanning / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000737:chemistry / Q000235:genetics; D009693:Nucleic Acid Hybridization / Q000379:methods; D015341:Nucleic Acid Probes / Q000737:chemistry*; D010316:Particle Size; D020135:Peptide Nucleic Acids / Q000737:chemistry*; D012680:Sensitivity and Specificity; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013499:Surface Properties
chemical_list: D000814:Aniline Compounds; D015341:Nucleic Acid Probes; D020135:Peptide Nucleic Acids; C416807:polyaniline; D006046:Gold; D004247:DNA; D008751:Methylene Blue