title: Ultrasensitive DNA sensor based on gold nanoparticles/reduced graphene oxide/glassy carbon electrode.
abstract: We have designed a simple and novel electrochemical biosensor based on glassy carbon electrode (GCE) for DNA detection. GCE was modified with reduced graphene oxide (RGO) and gold nanoparticles (AuNPs) by the electrochemical method, which is helpful for immobilization of thiolated bioreceptors. The electrode modification processes were characterized by scanning electron microscopy (SEM) and electrochemical methods. Then a single-stranded DNA (ssDNA) probe for BRCA1 5382 insC mutation detection was immobilized on the modified electrode for a specific time. The experimental conditions, such as probe immobilization time and target DNA (complementary DNA) hybridization time and temperature with probe DNA, were optimized using electrochemical methods. The electrochemical response for DNA hybridization and synthesis was measured using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) methods. The calibration graph contains two linear ranges; the first part is in the range of 3.0×10(-20) to 1.0×10(-12)M, and the second segment part is in the range of 1.0×10(-12) to 1.0×10(-7)M. The biosensor showed excellent selectivity for the detection of the complementary sequences from noncomplementary sequences, so it can be used for detection of breast cancer.
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, Yazd, Iran. Electronic address: benvidi89@gmail.com.
authors.forename: Ali
authors.initials: A
authors.lastname: Benvidi
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, Yazd, Iran.
authors.forename: Afsaneh Dehghani
authors.initials: AD
authors.lastname: Firouzabadi
authors.affiliation: Department of Biology, Faculty of Science, Yazd University, Yazd, Iran.
authors.forename: Seyed Mohammad
authors.initials: SM
authors.lastname: Moshtaghiun
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, Yazd, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Mazloum-Ardakani
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, Yazd, Iran.
authors.forename: Marzieh Dehghan
authors.initials: MD
authors.lastname: Tezerjani
mesh_terms: D019313:BRCA1 Protein / Q000235:genetics; D001483:Base Sequence; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004247:DNA / Q000032:analysis* / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D004252:DNA Mutational Analysis; D015342:DNA Probes / Q000737:chemistry / Q000235:genetics; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000235:genetics; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D004563:Electrochemistry; D004566:Electrodes; D005898:Glass / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D057230:Limit of Detection; D009693:Nucleic Acid Hybridization; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D015203:Reproducibility of Results
chemical_list: D019313:BRCA1 Protein; D015342:DNA Probes; D004277:DNA, Single-Stranded; D010087:Oxides; D006046:Gold; D006108:Graphite; D004247:DNA; D004259:DNA-Directed DNA Polymerase
keywords: Breast cancer detection; DNA biosensor; EIS; Gold nanoparticles; Graphene; Hybridization