Study of physicochemical properties of GNF-biocompatible hydrogel coatings by SECM

ELIANA D FARIAS; CLAUDIO MORTIER; ALEXANDER KUHN; PHILIPPE BARTHÉLEMY; DODZI ZIGAH

Workshop; 10th Workshop on SECM and Related Techniques; 2019

Controlling the interface between biological tissues and electrodes remains a big challenge for the development of implantable devices, because the biocompatibility of the electrode prevails as one of the major issues. Based on their intrinsic properties, hydrogels have been extensively studied in the biomedical context, including scaffolds for tissue engineering1, drug delivery carriers2, among others. These soft materials have the capacity to form building blocks, which can be held in solution and turned into a gel phase by changing physical (such as temperature) or chemical (pH, ionic strength) parameters. Low molecular weight gelators (LMWG) is a particular class of gel forming compounds. Glycosylated nucleoside fluorocarbon amphiphile (GNF) developed in the ChemBioPharm team of U1212 belongs to this family. Covering an electrode with this gel increase its biocompatibility3, thus allowing their application in implantable devices, such as biosensors, biofuel cell or drug delivery systems.Scanning ElectroChemical Microscopy (SECM) is an in situ local electrochemical probe technique that is well adapted to soft object imaging. Regarding permeable materials, SECM is able to reveal ion transport through a nanoporous membrane or for example quantify active sites at an interface. Electrode surfaces coated with the GNF hydrogels present new interesting properties, especially with respect to mass transport and charge transfer kinetics. These properties will depend on the method used to deposit the gel, its thickness, its density etc... To study these phenomena SECM is a perfect tool. By using a microelectrode to probe the gel, information about porosity, homogeneity, and reactivity can be extracted. In this work, we study the physicochemical properties of gold surfaces coated with GNF by changing parameters as thickness and density. Along this work, interfacial properties as well as fundamental studies of mass transport and charge transfer kinetics were investigated