title: 8-hydroxy-2'-deoxyguanosine (8-OHdG) biomarker detection down to picoMolar level on a plastic antibody film.
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 100pg/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.
authors.affiliation: BioMark/CINTESIS-ISEP, School of Engineering of the Polytechnique School of Porto, 4200-072 Porto, Portugal; i3N/CENIMAT, Department of Materials Science, Faculty of Sciences and Technology, Universidade NOVA de Lisboa and CEMOP/UNINOVA, Campus de Caparica, 2829-516 Caparica, Portugal.
authors.forename: Gabriela V
authors.initials: GV
authors.lastname: Martins
authors.affiliation: i3N/CENIMAT, Department of Materials Science, Faculty of Sciences and Technology, Universidade NOVA de Lisboa and CEMOP/UNINOVA, Campus de Caparica, 2829-516 Caparica, Portugal.
authors.forename: Ana C
authors.initials: AC
authors.lastname: Marques
authors.affiliation: i3N/CENIMAT, Department of Materials Science, Faculty of Sciences and Technology, Universidade NOVA de Lisboa and CEMOP/UNINOVA, Campus de Caparica, 2829-516 Caparica, Portugal.
authors.forename: Elvira
authors.initials: E
authors.lastname: Fortunato
authors.affiliation: BioMark/CINTESIS-ISEP, School of Engineering of the Polytechnique School of Porto, 4200-072 Porto, Portugal. Electronic address: goreti.sales@gmail.com.
authors.forename: M Goreti F
authors.initials: MGF
authors.lastname: Sales
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology; D015415:Biomarkers / Q000652:urine; D003217:Conductometry / Q000295:instrumentation*; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000276:immunology / Q000652:urine; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D008567:Membranes, Artificial; D054802:Molecular Imprinting / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000911:Antibodies, Monoclonal; D015415:Biomarkers; D008567:Membranes, Artificial; D006046:Gold; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine
keywords: 8-hydroxy-2′-deoxyguanosine; Electrochemical biosensor; Electropolymerization; Molecularly imprinted polymer; Urine biomarker