Labeless Photoelectrochemical and Impedimetric Aptasensors and Immunosensors Based on Biofunctionalized Electropolymerized Polymers (Keynote)

For four decades, the development of biointerfaces has been the subject of increasing research efforts in the field of biosensors and energy conversion. Owing to their high conductivity, inertness and electroactive surface area, graphene and carbon nanotube are widely used for the design of biosensors and their functionalization was successfully performed by electrogenerated polymers exhibiting affinity or covalent binding interactions towards biomolecules.

Recent examples of electropolymerized films will be presented for the design of labeless immunosensors and aptasensors for bisphenol A, cocaine, dengue antibody or cholera toxin antibody [1].

We report thus the synthesis and electrochemical characterization of a novel electropolymerizable Ru(II) complex bearing an intercalator group as well as the electrochemical behavior and photoelectrochemical properties of the resulting polymer film [2]. The latter was applied to the label-free photoelectrochemical detection of cocaine. A photoelectrode was thus designed by electrodeposition of a pyrrole monomer modified with a polypyridyl Ru(II) complex bearing benzo[i]dipyrido-[3,2-a:2'.3'-c]phenazine (dppn) ligand. Owing to the intercalating properties of these immobilized complexes towards DNA double helix, cocaine aptamer was immobilized on the modified electrodes thanks to its stem-loop configuration in order to design a photoelectrochemical cocaine aptasensor. The detection of cocaine via the formation of the aptamer/cocaine complex was successfully observed via a decrease in the photocurrent intensity. The photoelectrochemical aptasensor exhibits a detection limit of 10 nmol L-1 and linear range of 1 10-8 to 5 10-4 mol L-1 [3].