서강대학교

초록/요약

The electrochemical sensors are currently receiving tremendous attention in bio-medical technology and environmental protection since they can comply with the considerable demand for reliable, sensitive and low-cost analysis tools. The preparation of the electrochemical sensors with high sensitivity, enough stability and selectivity is required for the efficient analysis. The redox polymer and their composites effectively satisfy the requirements to modify the electrode for the preparation of electrochemical sensors. In the present work the redox polymers and their composites with silica, carbon nanoparticles and chitosan polymer were used for the electrode modification and their electrochemical sensing properties were studied. (1) The ferrocene modified polyacrylic acid were used for the successful immobilization of horseradish peroxidase (HRP) or glucose oxidase (GOx) in the composite film and it showed a linear response up to 0.5 mM for hydrogen peroxide and 10 mM for glucose with the sensitivity of 1.9 µA. mM-1 cm-2. (2) The silica composite of the ferrocene modified polyvinyl alcohol showed the sulfite oxidation at 0.3 V with the detection limit of 1.5 × 10-7 M. (3) The effect of chitosan composite to the osmium polymer (PVP-Os) was tested and it shows the apparent diffusion coefficient of charge hopping is 1.8 × 10-9 cm2/s without chitosan and 3 × 10-7 cm2/s with chitosan. The sensitivity of the PVP-Os/Cs/GOx for the glucose sensing was found to be 1.1 μA. mM-1 cm-2 and for PVP-Os/GOx was 0.137 μA. mM-1 cm-2. The nanocomposite of hydroquinone modified chitosan with carbon nanoparticles shows selective detection of the ascorbic acid in the linear range 10 μM to 5 mM. The catechol modified chitosan with carbon nanoparticle shows NADH oxidation at 0.165 V with the detection limit of 3.5 × 10-8 M and the sensitivity of 1.06 μA. μM-1 cm-2. The Cu, Mn, Fe salen modified chitosan polymer having good solubility in aqueous acidic solutions were prepared and their composite with carbon nanoparticles used for the selective detection of the hydrogen peroxide.