Studies On The Application Of Reduccd Graphene Oxide Modified Electrodes In Elecrochemical Sensors And Biosensors

In this thesis, efforts have been devoted to the fabrication of sensor based on thereduced graphene oxide composite modified carbon electrode. The dissertation consistsof three main parts: Amperometric glucose biosensor based on integration of glucoseoxidase with palladium nanoparticles/reduced graphene o xide nanocomposite;electrochemical NADH biosensor based on thionine/reduced graphene oxide compositemodified glassy carbon electrode; and electrochemical ascorbic acid sensor and NADHbiosensor based on redox reduced graphene oxide prepared by noncovalen tfunctionalization with1,10-phenanthroline-5,6-dione.(1) The Pd/RGO nanocomposite was prepared by a one-step chemical reductionmethod. The as-prepared nonocompsite exhibits faborable electrocatalytic actibitiestowards H2O2, which makes it a good platform for the construction of the glucosebiosensor. The analytical performance of the glucose biosensor is fully evaluated. Itshows good analytical properties in terms of a short response time (3s), high sensitivity(14.1μA·mM-1), and low detection limit (0.034mM, signal-to-noise of3).(2) A thionine/reduced graphene oxide electrode (TH/RGO/GCE) was prepared byadsorbing thionine to electrochemical-reduced graphene oxide electrode in our lab. Westudied the kinetic performance of TH/RGO/GCE and the significant electrocatalyticactivity towards NADH of TH/RGO/GCE. Under optional potential NADH could bedetermined in the wide linear range to1mM with detection limit0.035μΜ(signal-to-noise of3) and a high sensitivity6.44μA·mM-1, suggesting the goodanalytical performance of the NADH biosensor.(3)1,10-phenanthroline-5,6-dione (PD) functionalized reduced graphene oxide(chemical reduced method) nanocomposite film modified glassy cabon electrode(PD/RGO/GCE) has been fabricated The PD/RGO/GCE showed promoted electron kinetics,in some extent resulting significant electrocatalytic activity towards ascorbic acid (AA) andNADH, which encourage us to establish an electrochemical method for the detemination ofAA and NADH. The AA electrochemical sensor and NADH biosensor show remarkableanalytical characteristics, moreover, the electrochemical AA sensor has satisfiedperformances in real sample measurements.