BIOSENSING WITH ELECTROCONDUCTIVE BIOMIMETIC SOFT MATERIALS

Electrochemical sensors based on microstructured electrodes represent one of the most promising technological solutions for biological monitoring because of the amount of possibilities that electrical signaling offers and the possibility of realizing microstructured systems with high specificity and sensitivity. The development of these devices may be improved by the availability of soft biocompatible electroactive materials. The latter are an innovative answer in this context because of they can be manipulated, doped or functionalized in order to realize a biological transducer. In our work we have investigated the possibility of using polyacrylamide hydrogels (HYs) doped with Single-Walled Carbon Nanotubes (SWCNTs) in order to achieve the electroconduction, then loaded with a specific enzyme for glucose detection (Glucose Oxidase, GOx). The electrical analysis was performed by means of Electrochemical Impedance Spectroscopy (EIS) characterization of polarization resistance of the equivalent circuit model. Although GOx-doped hydrogels do not exhibit any electrical activity to glucose in measurements, GOx-SWNT doped hydrogels show glucose-concentration linear response in the range between 0.1 mM to 1.6 mM; all together this result show high sensitivity (up to 15 uM) of glucose detection. In addition, dielectrophoresis (DEP) was applied to doped HYs in order to align SWCNTs in the materials as a proof of concept for increasing the sensitivity of the organic biosensor. The results and the possibility of HY functionalization allow the device to be integrated in cell culture systems in order to allow the detection and the acquisition of electrochemical associated biological phenomena.