Electrochemical DNA-biosensors based on long-range electron transfer: optimization of the amperometric detection in the femtomolar range using two-electrode setup and ultramicroelectrode

A. Nassi , F-X. Guillon (1) , A. Amar (1) , B. Hainque (1) , S. Amriche (1) , D. Mauge (1) , E. Markova (2) , C. Tse , P. Bigey (1) , M. Lazerges (1) , F. Bedioui (1)

1 UTCBS - UM 4 (UMR 8258 / U1022) - Unité de Technologies Chimiques et Biologiques pour la Santé
2 RCPTM - Regional Centre of Advanced Technologies and Materials [Olomouc]

We report on the design of electrochemical DNA-biosensors made from 15, 25 and 50 mm diameter gold ultramicroelectrodes (UMEs) in a two-electrode setup. The biosensors were prepared by chemical adsorption of 22-base thiol-labeled DNA-probes in a self-assembled monolayer configuration onto the surface of the gold UME. Hybridization events were transduced by Fe-III/Fe-II redox process electromediated by DNA-redox intercalated mediators. The optimization of the DNA-biosensors was achieved by using different FeIII/FeII ligands (cyanide, cefadroxil, deferoxamine) and intercalators (methylene blue, proflavine). Optimized biosensors allowed direct and selective amperometric detection in the femtomolar range and of single mismatch within a 35 minutes protocol. (C) 2016 Elsevier Ltd. All rights reserved.

Keywords: GLASSY-CARBON ELECTRODE; SEQUENCE-SPECIFIC DNA; NUCLEIC-ACID PROBES; HEPATITIS-B-VIRUS; METHYLENE-BLUE; HYBRIDIZATION BIOSENSOR; LABEL; POLYPYRROLE; FILMS; IMMOBILIZATION

Domains: Life Sciences [q-bio]; Biotechnology; Chemical Sciences; Analytical chemistry

A. Nassi, F-X. Guillon, A. Amar, B. Hainque, S. Amriche, et al.. Electrochemical DNA-biosensors based on long-range electron transfer: optimization of the amperometric detection in the femtomolar range using two-electrode setup and ultramicroelectrode. Electrochimica Acta, 2016, 209, pp.269-277. ⟨10.1016/j.electacta.2016.04.144⟩. ⟨hal-03292058⟩