Micro-electrodes Biosensor: New Approach to Study Bio-material Hydrogels Characteristics Such As Swelling / Deswelling, Porosity

The new design of an Impedance measurement based sensor is integrated into the standard 96 wells microtiter plate which is use for characterizing different stimulus hydrogels. The online monitoring of swelling and deswelling of hydrogel is possible with this new system. Hydrogels of Poly-Hydroxyethyle Methacrylate, Poly (HEMA) with different compositions of mixing monomers were used for measurements. These hydrogels which absorbs/desorbs solution in response to changes in surrounding environmental condition polymerized over the sensor with roughly 200µm height. The sensor output voltage response to pH value changes with swelling and contracting of hydrogel. The shift in the resistivity of hydrogel was investigated as function of different mixing monomers ratios and compartment of hydrogel. It was found the concentration of cross-link and water content play significant role in changing resistivity of hydrogel. An additional advantage with new setup its use only 200µl of solution and 200µm thick hydrogel layer in standard 96 wells microtiter plate for characterizing hydrogels.