title: A DNA biosensor based on the electrocatalytic oxidation of amine by a threading intercalator.
abstract: An electrochemical biosensor for the detection of DNA based a peptide nucleic acid (PNA) capture probe (CP) modified indium tin oxide electrode (ITO) is described in this report. After hybridization, a threading intercalator, N,N'-bis[(3-propyl)-imidazole]-1,4,5,8-naphthalene diimide (PIND) imidazole complexed with Ru(bpy)(2)Cl (PIND-Ru, bpy=2,2'-bipyridine), was introduced to the biosensor. PIND-Ru selectively intercalated to double-stranded DNA (ds-DNA) and became immobilized on the biosensor surface. Voltammetric tests showed highly stable and reversible electrochemical oxidation/reduction processes and the peak currents can directly be utilized for DNA quantification. When the tests were conducted in an amine-containing medium, Tris-HCl buffer for example, a remarkable improvement in the voltammetric response and noticeable enhancements of voltammetric and amperometric sensitivities were observed due to the electrocatalytic activity of the [Ru(bpy)(2)Cl] redox moieties. Electrocatalytic current was observed when as little as 3.0attomoles of DNA was present in the sample solution.
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, Singapore 138669, Singapore. zqgao@ibn.a-star.edu.sg
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Gao
authors.forename: Natalia
authors.initials: N
authors.lastname: Tansil
mesh_terms: D000588:Amines / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D002384:Catalysis; D004247:DNA / Q000032:analysis / Q000737:chemistry*; D004566:Electrodes; D007364:Intercalating Agents / Q000737:chemistry*; D009281:Naphthalenes / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry; D010084:Oxidation-Reduction; D020135:Peptide Nucleic Acids / Q000737:chemistry; D011199:Potentiometry; D012680:Sensitivity and Specificity; D017971:Tin Compounds / Q000737:chemistry
chemical_list: D000588:Amines; D007364:Intercalating Agents; D009281:Naphthalenes; D009942:Organometallic Compounds; C518125:PIND-Ru; D020135:Peptide Nucleic Acids; D017971:Tin Compounds; C109984:indium tin oxide; D004247:DNA