8-hydroxy-2′-deoxyguanosine (8-OHdG) biomarker detection down to picoMolar level on a plastic antibody film

Gabriela V. Martins, Ana Cláudia Lourenço Santana Marques, Elvira Fortunato, M. Goreti F Sales

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

An innovative biosensor assembly relying on a simple and straightforward in-situ construction is presented to monitor urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) down to the pmol/L level. The sensing film of the biosensor consisted of a molecularly imprinted polymer (MIP) layer for 8-OHdG assembled on a gold electrode through electropolymerization of monomer combined with the template. The analytical features of the resulting biosensor were assessed by Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS). Some experimental parameters such as the initial concentration of the monomer and the ratio template-monomer were investigated and optimized in order to finely tune the performance of the MIP-based sensor. Under optimal conditions, the developed biosensor was able to rebind 8-OHdG with a linear response against EIS from 0.1 to 100 pg/ml 3.5-3500 pM. The interference of coexisting species was tested, also with calibrations on urine samples, and good selectivity towards 8-OHdG was obtained. RAMAN spectroscopy, FTIR and SEM evaluations of the prepared films confirmed the formation of a polyphenol thin-film on the electrode surface. The presence and distribution of the imprinted cavities on the MIP layer was confirmed by confocal microscopy imaging of the film, after a post-treatment with Fluorescein Isothiocyanate (FITC) labeled 8-OHdG antibody. Overall, this label-free biosensor for urinary 8-OHdG detection constitutes a promising low-cost alternative to the conventional immunoassay approaches, due to its simplicity, stability, high sensitivity and selectivity for biological sample assays, opening new doors for other applications.

Original languageEnglish
Pages (from-to)225-234
Number of pages10
JournalBiosensors & Bioelectronics
Volume86
DOIs
Publication statusPublished - 15 Dec 2016

Keywords

  • MOLECULARLY IMPRINTED POLYMERS
  • OXIDATIVE DNA-DAMAGE
  • SCREEN-PRINTED ELECTRODES
  • GLASSY-CARBON ELECTRODE
  • ELECTROCHEMICAL SENSOR
  • URINARY 8-HYDROXY-2'-DEOXYGUANOSINE
  • CAPILLARY-ELECTROPHORESIS
  • GOLD NANOPARTICLES
  • CANCER-PATIENTS
  • STRESS

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