The Study Of Ascorbic Acid Biosensor

In the present thesis, the applications of several materials in electrochemical sensor havebeen studied. The metal organic framework compound (MOFs), conducting polymer,nanomaterial and biological dye were modified onto the bare glassy carbon electrode byelectrodeposition, electrochemical polymerization and layer-by-layer self assembly technique,respectively. A series of novel ascorbic acid biosensors were fabricated for the determinationof ascorbic acid (AA), and the simultaneous determination of ascorbic acid (AA) andacetaminophen (ACOP). The results showed that these materials can enhance theelectrochemical performance of electrode.Firstly, Using electrodepositing technique,[Li-BDC]/GC electrode was fabricated.Selecting ascorbic acid (AA) as probe, the electrochemical performances of this modifiedelectrode were investigated by cyclic voltammetry. The results showed that [Li-BDC]/GCelectrode showed excellent performances to the determination of AA. The linear range from3.0×10-7to2.5×10-3M was obtained and the detection limit was6.0×10-8M (S/N=3:1). Thismethod has been used to determine AA in vitamin C tablets with satisfactory results.Secondly，a diethylene glycolic acid (DA) modified electrode has been fabricated byelectrochemical polymerization. The electrochemical performance of the modified electrodewas investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Usingdifferential pulse voltammetry (DPV) simultaneous detected ascorbic acid and acetaminophen,and the peak separation between ascorbic acid (AA) and acetaminophen (ACOP) was large upto364mV.Finally, using layer-by-layer self assembly technique, NGB/MWCNTs/GC wasfabricated. And the electro-catalytic activity of the modified electrode was discussed. Theresults showed preferable performances to the determination of AA. They will provide a newplatform for fabricating electrochemical sensor.