Synthesis Of Mesoporous Carbon Material And Its Study On Laccase Biosensor

This subject based on researching a novel immobilization material of enzyme, ordered mesoporous carbon(OMC), which was synthesized, not only had the performance of electronical activity that guaranteed the redox activity of enzyme biosensor, but also had the structure of nanometer passageway that was advantageous in an immobilization of enzyme and maintenance of biological activity of biosensor, and further improved properties of sensors. Laccase(Lac) biosensor has the specific character of convenience, high sensitivity,rapid response and wide application prospects. Therefore, Lac was selected as the enzyme to fabricate a biosensor with OMC modified electrode to determinate catechol in sewage, which provides a new idea in the environmental monitoring.A novel ordered mesoporous carbon (NOMC) was prepared through hard-template method with organic cross-linked water-solubility epoxy resin as carbon resource and SBA-15 as template reagent, which has the performance of electrocatalysis activeness. Ultraviolet-visible (UV-vis) spectrum showed NOMC contains manyπelectrons. Transmission electron microscopy (TEM) indicated that NOMC has the typical two-dimensional ordered hexagon mesostructure with about 3nm of hole diameter. The results of cyclic volt-ampere (CV) tests showed the reactive process of the NOMC modified Au electrode in buffer solution was one proton-one electron participated and reversible surface-controlling process.The Lac biosensor with NOMC as the immobilized enzyme material was firstly fabricated. The NOMC/Lac/Au electrode could catalyze catechol, whose peak values of oxidative current and reductive current all linearly increased with the elevation of scanning rate, and its process was one proton-one electron reversible surface controlling. Among biosensors prepared with different immobilized methods, the overall properties of Lac biosensor built by static electricity adsorption of PDDA was best. The linear response range of the Lac biosensor was 0.67~8.59μM, its sensitivity was 0.349A/M, Michaelis constant was 13.49mM, and its detection limitation was 0.117μM(S/N=3).A functionalized mesoporous carbon (CuO-OMC) was synthesized to improve the electrocatalysis of the OMC. TEM and EDS tests showed that CuO-OMC has homogeneous ordered mesoporous structure without the silicon element, and that the copper element was successively loaded in the passage of OMC. CV tests indicated that CuO-OMC modified Au electrode had a fine ability of electrochemistry in the PBS solution. The CuO-OMC/Lac/Au electrode with chitosan as membrane material was fabricated and displayed more excellent sensing performances at the room temperature of 25±2℃, the working potencial of +0.45V vs SCE and the PBS solution of pH value 5.2: the linear response range was 0.67~15.75μM, Michaelis constant 40.25μM, detection limitation 0.807μM(S/N=3) , respectively. Additionally, this biosensor has good reproduction quality and stability. Therefore, OMC as a novel immobilized material of enzyme can elevate the performance of electrotransferring and sensitivity, and can reduce the detection limitation of enzyme biosensor.