title: Nanostructured rough gold electrodes as platforms to enhance the sensitivity of electrochemical genosensors.
abstract: An electrochemical DNA genosensor constructed by using rough gold as electrode support is reported in this work. The electrode surface nanopatterning was accomplished by repetitive square-wave perturbing potential (RSWPP). A synthetic 25-mer DNA capture probe, modified at the 5' end with a hexaalkylthiol, able to hybridize with a specific sequence of lacZ gene from the Enterobacteriaceae bacterial family was assembled to the rough gold surface. A 25 bases synthetic sequence fully complementary to the thiolated DNA capture probe and a 326 bases fragment of lacZ containing a fully matched sequence with the capture probe, which was amplified by a specific asymmetric polymerase chain reaction (aPCR), were employed as target sequences. The hybridization event was electrochemically monitored by using two different indicators, hexaammineruthenium (III) chloride showing an electrostatic DNA binding mode, and pentaamineruthenium-[3-(2-phenanthren-9-yl-vinyl)-pyridine] (in brief RuL) which binds to double stranded DNA (dsDNA) following an intercalative mechanism. After optimization of the different variables involved in the hybridization and detection reactions, detection limits of 5.30 pg μL(-1) and 10 pg μL(-1) were obtained for the 25-mer synthetic target DNA and the aPCR amplicon, respectively. A RSD value of 6% was obtained for measurements carried out with 3 different genosensors prepared in the same manner.
authors.affiliation: Department of Analytical Chemistry and Instrumental Analysis, Universidad Autónoma de Madrid, 28049 Madrid, Spain. tania.garcia@uam.es
authors.forename: T
authors.initials: T
authors.lastname: García-Mendiola
authors.forename: M
authors.initials: M
authors.lastname: Gamero
authors.forename: S
authors.initials: S
authors.lastname: Campuzano
authors.forename: M
authors.initials: M
authors.lastname: Revenga-Parra
authors.forename: C
authors.initials: C
authors.lastname: Alonso
authors.forename: M
authors.initials: M
authors.lastname: Pedrero
authors.forename: F
authors.initials: F
authors.lastname: Pariente
authors.forename: J M
authors.initials: JM
authors.lastname: Pingarrón
authors.forename: E
authors.initials: E
authors.lastname: Lorenzo
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D056831:Coordination Complexes / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D004755:Enterobacteriaceae / Q000235:genetics; D006046:Gold; D007763:Lac Operon; D049329:Nanostructures; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000032:analysis; D016133:Polymerase Chain Reaction; D017975:Ruthenium Compounds; D012680:Sensitivity and Specificity; D055672:Static Electricity
chemical_list: D056831:Coordination Complexes; D009841:Oligonucleotides; D017975:Ruthenium Compounds; C585058:pentaamineruthenium-(3-(2-phenanthren-9-ylvinyl)pyridine); C031584:hexammineruthenium; D006046:Gold
keywords: Asymmetric polymerase chain reaction; Electrochemical detection; Genosensor; Nanopatterning; Rough gold electrode