Electrochemical DNA biosensor for detecting cancer biomarker related to glutathione <i>S</i>-transferase P1 (<i>GSTP1</i>) hypermethylation in real samples

TOPKAYA ÇETİN S. N., ARIKSOYSAL D., KOSOVA B., Ozel R., Ozsoz M.

BIOSENSORS & BIOELECTRONICS, cilt.31, sa.1, ss.516-522, 2012 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 31 Sayı: 1
  • Basım Tarihi: 2012
  • Doi Numarası: 10.1016/j.bios.2011.11.029
  • Dergi Adı: BIOSENSORS & BIOELECTRONICS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.516-522
  • Anahtar Kelimeler: Electrochemical DNA biosensor, Differential pulse voltammetry (DPV), Electrochemical impedance spectroscopy (EIS), Cancer marker, Glutathione S-transferase P1 hypermethylation
  • Dokuz Eylül Üniversitesi Adresli: Hayır

Özet

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-mu l reaction volume. The optimum analytical detection parameters for the biosensor, as well as its future prospects, were also presented. (C) 2011 Elsevier B.V. All rights reserved.