earticle

영어

In the last few years, considerable attention has been devoted to the immobilization of biomolecules, especially enzymes on electrode surface in relation to the development of biosensors and biotechnological processes. In this work, we immobilized HRP onto the bifunctional silane 3‐aminopropyltrimethoxy silane (APTMOS) through glutaraldehyde crosslinker. Separately, the organic mediator Neutral red was covalently crosslinked to 3‐aminopropyltrimethoxy silane using glutaraldehyde. The primary amino groups on the mediators, enzyme and the sol‐gel precursor were of advantage in the motive for covalent immobilization. Methyl trimethoxy silane was used as an additional sol‐gel monomer to maintain the hydrophilic/hydrophobic nature of the composite. The composite electrode was prepared using the above two silane mixtures along with graphite powder. The electrochemical behavior of the modified electrode was probed in using cyclic voltammetry. The biosensing application of the modified electrode was verified using hydrogen peroxide as the substrate. The biosensor showed a good linear response towards hydrogen peroxide in the range of 2.14 x 10‐7 M to 1.93 x 10‐4 M with a detection limit of 1.28 x 10‐7 M.
Kinetic parameters such as electron transfer rate constant, ks was evaluated to be 0.30 ± 0.03 s‐1 and the diffusion coefficient, α was found to be 0.27 by applying the Laviron’s method [1]. The chronoamperometric studies showed that the biosensor could sense effectively in dynamic mode. The performance of the biosensor was optimized with respect the scan rate, pH and temperature.