| Two approaches leading to the development of amperometric biosensors were undertaken. Electrostatic assembly was utilized to create nanocomposite films consisting of positively charged organomettalic redox polymers and negatively charged oxidoreductase enzymes. Assembly on gold surfaces was verified by surface plasmon resonance (SPR) spectroscopy, grazing angle FTIR and ellipsometry. Immobilization of these composite films on gold microelectrode arrays resulted in formation of redundant sensors for glucose, lactate and pyruvate detection. Substrate calibration curves were generated by means of cyclic voltammetry and time-based amperometry.; Photolithographic patterning of poly(ethylene glycol) was employed to fabricated cross-linked hydrogel microstructures on planar substrates. Ability to create high quality polymer patterns of various molecular weights and geometrical configurations was demonstrated. Chlorosilane coupling chemistry was introduced to insure covalent bonding of cross-linked polymer to the substrate. In addition, hydrogel microstructures were also patterned on gold and polymeric materials. Potential usefulness of this patterning approach in amperometric sensing was ascertained by selective deposition of hydrogel elements onto gold electrodes. Furthermore, in vitro biocompatibility of the hydroget films was demonstrated. |
