title: Electrochemical DNA biosensor for detecting cancer biomarker related to glutathione S-transferase P1 (GSTP1) hypermethylation in real samples.
abstract: An electrochemical genosensor for the detection of hypermethylation of the glutathione S-transferase P1 (GSTP1) gene, a specific marker of prostate cancer, was reported. This new sensor was used in combination with a single-use carbon graphite working electrode and differential pulse voltammetry, with the results of sample analysis based on the guanine oxidation signals obtained at +1.0 V before and after hybridization between probe and synthetic target or denatured PCR samples. The detected DNA hybridization was also characterized by electrochemical impedance spectroscopy with potassium ferri/ferrocyanide as a redox probe. The protocol consisted of 2 different modes: (i) capture probes selective for methylation-specific and unmethylated GSTP1 sequences were immobilized onto the sensor directly, and hybridization was formed on the electrode surface; (ii) probe/target or probe/noncomplementary target couples were mixed in solution phase, and the transducer was modified through simple adsorption. The limit of detection (S/N=3) was calculated as 2.92 pmol of target sequence in a 100-μl reaction volume. The optimum analytical detection parameters for the biosensor, as well as its future prospects, were also presented.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, Ege University, Izmir, Turkey.
authors.forename: Seda Nur
authors.initials: SN
authors.lastname: Topkaya
authors.forename: Dilsat
authors.initials: D
authors.lastname: Ozkan-Ariksoysal
authors.forename: Buket
authors.initials: B
authors.lastname: Kosova
authors.forename: Rukiye
authors.initials: R
authors.lastname: Ozel
authors.forename: Mehmet
authors.initials: M
authors.lastname: Ozsoz
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics*; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D051549:Glutathione S-Transferase pi / Q000032:analysis / Q000235:genetics*; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000201:enzymology* / Q000235:genetics*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000295:instrumentation*
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; C496556:GSTP1 protein, human; D051549:Glutathione S-Transferase pi