title: Electrochemical detection of a breast cancer susceptible gene using cDNA immobilized chitosan-co-polyaniline electrode.
abstract: An electrochemical breast cancer biosensor based on a chitosan-co-polyaniline (CHIT-co-PANI) copolymer coated onto indium-tin-oxide (ITO) was fabricated by immobilizing the complementary DNA (cDNA) probe (42 bases long) associated with the breast cancer susceptible gene BRCA1. Both the CHIT-co-PANI/ITO and the cDNA/CHIT-co-PANI/ITO electrodes were characterized with Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). For the cDNA/CHIT-co-PANI/ITO electrode, the amperometric current decreased linearly with an increasing logarithm of molar concentration of the single-stranded target DNA (ssDNA) within the range of 0.05-25fmol. The bioelectrode exhibited a sensitivity of 2.104 microA/fmol with a response time of 16s. The cDNA/CHIT-co-PANI/ITO electrode had a shelf life of about six months, even when stored at room temperature.
authors.affiliation: Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, WI 532011, USA. tiwari@uwm.edu
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Tiwari
authors.forename: Shaoqin
authors.initials: S
authors.lastname: Gong
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D001943:Breast Neoplasms / Q000175:diagnosis / Q000235:genetics*; D002138:Calibration; D048271:Chitosan / Q000737:chemistry*; D018076:DNA, Complementary / Q000737:chemistry* / Q000235:genetics* / Q000648:ultrastructure; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D018625:Microscopy, Atomic Force; D015394:Molecular Structure; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000814:Aniline Compounds; D018076:DNA, Complementary; C416807:polyaniline; D048271:Chitosan