title: Label-free electrochemical detection of the specific oligonucleotide sequence of dengue virus type 1 on pencil graphite electrodes.
abstract: A biosensor that relies on the adsorption immobilization of the 18-mer single-stranded nucleic acid related to dengue virus gene 1 on activated pencil graphite was developed. Hybridization between the probe and its complementary oligonucleotides (the target) was investigated by monitoring guanine oxidation by differential pulse voltammetry (DPV). The pencil graphite electrode was made of ordinary pencil lead (type 4B). The polished surface of the working electrode was activated by applying a potential of 1.8 V for 5 min. Afterward, the dengue oligonucleotides probe was immobilized on the activated electrode by applying 0.5 V to the electrode in 0.5 M acetate buffer (pH 5.0) for 5 min. The hybridization process was carried out by incubating at the annealing temperature of the oligonucleotides. A time of five minutes and concentration of 1 μM were found to be the optimal conditions for probe immobilization. The electrochemical detection of annealing between the DNA probe (TS-1P) immobilized on the modified electrode, and the target (TS-1T) was achieved. The target could be quantified in a range from 1 to 40 nM with good linearity and a detection limit of 0.92 nM. The specificity of the electrochemical biosensor was tested using non-complementary sequences of dengue virus 2 and 3.
authors.affiliation: Laboratory of Immunopathology Keizo Asami (LIKA), Universidade Federal de Pernambuco-UFPE, Recife, PE, Brazil. elainevms@yahoo.com.br
authors.forename: Elaine
authors.initials: E
authors.lastname: Souza
authors.forename: Gustavo
authors.initials: G
authors.lastname: Nascimento
authors.forename: Nataly
authors.initials: N
authors.lastname: Santana
authors.forename: Danielly
authors.initials: D
authors.lastname: Ferreira
authors.forename: Manoel
authors.initials: M
authors.lastname: Lima
authors.forename: Edna
authors.initials: E
authors.lastname: Natividade
authors.forename: Danyelly
authors.initials: D
authors.lastname: Martins
authors.forename: José
authors.initials: J
authors.lastname: Lima-Filho
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques / Q000379:methods*; D019295:Computational Biology / Q000379:methods; D015342:DNA Probes / Q000737:chemistry; D004279:DNA, Viral / Q000235:genetics*; D003716:Dengue Virus / Q000235:genetics*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D006147:Guanine / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009693:Nucleic Acid Hybridization; D009696:Nucleic Acids / Q000737:chemistry; D009841:Oligonucleotides / Q000737:chemistry; D013997:Time Factors
chemical_list: D015342:DNA Probes; D004279:DNA, Viral; D009696:Nucleic Acids; D009841:Oligonucleotides; D006147:Guanine; D006108:Graphite