Rational Functionalization Of Two Kinds Of Carbon-based Materials And Relative Electrochemical Devices

Carbon Materials possess many distinguished characteristics including good electrical conductivity, high purity, diversified structures, cheap, and more readily available. Carbon materials have a wide potential window (-1.0～1.0V vs.SCE) in aqueous solution. In addition, carbon materials are relatively chemically inert and can keep fairly high surface activity. These distinct characteristics essentially endow carbon materials with extensive applications in electrochemistry and electroanalytical chemistry.In this paper, two kinds of carbon materials, carbon nanotube and carbon hollow sphere, are used as electrode materials and functionalized rationally. Based on this, relative electrochemical devices such as chemo/biosensing and biofuel cell are constructed. The details are summarized as follows:1. Preparation of carbon nanotube/phenosafranine nanocomposites (PS-MWNTs) and its chemo/biosensing applications. The PS-MWNTs nanocomposites, in which phenosafranine (PS) used as electrocatalyst and MWNTs as electrode substrate, are prepared via adsorption andπ-πelectronic stack. A hydrogen peroxide (H2O2) sensor is constructed based on electrocatalytic activity of PS-MWNTs nanocomposite to H2O2. Under the optimum experimental conditions, the linear range of the sensor is 0-7 mM with a detection limit of 0.23μM. The GOx-PS-MWNTs bionanocomposites, in which GOx (glucose oxidase) is used as biocatalyst to glucose oxidation and PS-MWNTs as electrocatalyst to oxygen reduction, are also prepared, and as thus a glucose sensor is constructed based on the amount of oxygen comsumed in the glucose oxidation reaction catalysed by GOx. Under optimum experimental conditions, the linear range for glucose sensing is 0-8 mM, with a detection limit of 0.35μM.2. A micro-structured carbon hollow spheres (CPS) are synthesized. Firstly, the catalytic activity of CPS to NADH oxidation is studied and also a lactate biosensor based on lactate dehydrogenase (LDH) is constructed. The direct electrochemistry of bilirubin oxidase (BOD) on CDS/GC electrode is investigated. And as thus a membrane-less enzymatic lactate/O2 biofuel cell is constructed using LDH-CDS/GC electrode as bioanode and BOD-CDS/GC as biocathode. The biofuel cell is found to have open potential of 0.45 V and a maximum power output of 0.52μW/cm~2. Secondly, in order to improve the catalytic activity to NADH oxidation, a electrocatalyst to NADH oxidation, poly(methyl Blue) is further immobilized on CDS/GC electrode via electropolymerization. And as thus another lactate biosensor based on lactate dehydrogenase is constructed and also a membrane-less enzymatic lactate/O2 biofuel cell using LDH-polyMB-CDS/GC as bioande and BOD-CDS/GC as biocathode is also construted. The biofuel cell is found to have open potential of 0.6 V and a maximum power output of 3.13μW/cm~2.