Preparation Of Novel Chemically Modified Electrodes And Their Application In Biosensing And Electrocatalysis

The aim of chemically modified electrodes is to carry out the molecular design on the electrode surface. In other words, to immobilize molecular, ion and polymer with excellent properties on electrode surface and make the electrode specially chemical and physical properties. The application of chemically modified electrodes has involved in chemistry, life science, medicine, environment, food and militarization, and so on. This dissertation was concentrated on the use of various materials and modification methods to prepare novel chemically modified electrodes in biosensing and electrocatalysis. The preparations of novel amperometric glucose biosensors and modified electrodes containing polyoxometalates or room-temperature ionic liquids have been evaluated. Their micrographs, structure, properties and applications have been investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), current-time (i-t) and Tafel polarization technique, etc. The main points of this dissertation are summarized as follows:(1) An amperometic glucose biosensor based on carbon nanotubes (CNT) and organic non-conducting poly(o-aminophenol) (POAP) composite film was fabricated. CNT, glucose oxidase (GOD) and o-aminophenol were electrochemically co-polymerized at gold (Au) electrode. The micrographs of modified electrode were characterized by SEM. The electrocatalytic properties of Au/POAP/CNT/GOD electrode to glucose have been investigated by CV and i-t methods in detail. The detection limit, maximum current and sensitivity of Au/POAP/CNT/GOD electrode are 0.01 mM, 0.24 mA cm-2 and 11.4 mA M-1 cm-2, respectively.(2) An amperometic glucose biosensor based on copper (Cu) microparticles and non-conducting poly(o-aminophenol) (POAP) film was fabricated. Cu microparticles were electrodeposited on Au electrode by using potentiostatic method. The micrographs and element composition of Au/Cu electrode were characterized by SEM and EDS. The electrocatalytic properties of Au/Cu/POAP/GOD electrode to glucose have been investigated by CV and i-t methods in detail. The detection limit, maximum current and sensitivity of Au/Cu/POAP/GOD electrode are 0.01 mM, 0.45 mA cm-2 and 12.6 mA M-1 cm-2, respectively. Additionally, the Au/Cu/POAP/GOD electrode has good stability, reproducibility and applicability to whole blood analysis.(3) A novel amperometric glucose biosensor based on inorganic conducting Prussian blue (PB) film and organic non-conducting poly(o-aminophenol)...