title: Amplified label-free electrocatalytic detection of DNA in the presence of calcium ions.
abstract: A new label-free electrocatalytic method for the detection of DNA, is presented, in which DNA is the catalyst. The method takes advantage of the catalytic properties of the electrooxidised adenines within DNA toward the oxidation of NADH. This catalytic event results in an enhancement in the oxidation current of the electrooxidised adenines within DNA. Further improvement in this analytical signal is achieved in the presence of Ca(2+) ions. Parameters affecting the electrocatalytic current, such as pH or concentration of Ca(2+) ions have been investigated and optimised. Finally, the analytical features of the developed method are obtained. This method constitutes a more sensitive and reproducible alternative to other methods that use the oxidation current of the electrooxidised adenines without coupling to any catalytic event. A limit of detection of 33 fmol deoxyadenylic acid icosanucleotide (dA)(20), is obtained without labels.
authors.affiliation: Departamento de Química Física y Analítica, Universidad de Oviedo, C/Julián Clavería 8, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: de-los-Santos-Alvarez
authors.forename: Noemí
authors.initials: N
authors.lastname: de-los-Santos-Alvarez
authors.forename: M Jesús
authors.initials: MJ
authors.lastname: Lobo-Castañón
authors.forename: Arturo J
authors.initials: AJ
authors.lastname: Miranda-Ordieres
authors.forename: Paulino
authors.initials: P
authors.lastname: Tuñón-Blanco
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002118:Calcium / Q000737:chemistry*; D002384:Catalysis; D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D009243:NAD / Q000737:chemistry*; D021141:Nucleic Acid Amplification Techniques; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013194:Staining and Labeling
chemical_list: D009243:NAD; D004247:DNA; D002118:Calcium