Preparation And Application Of Biosensors Based On Carbon Nano Materials

Since the discovery of fullerenes (C₆₀) in 1985 and carbon nanotube (CNT) in 1991, they have attracted increasing attention because of their particular structural,unique physical,chemical and electric properties. Recently, with the development of studying of these materials, more and more researchers used these carbon nano materials as biological sensors in the field of biology and received satisfactory results. In order to broaden the scope of application of these materials in the field of biological analysis, we did some research about these cabon nano material in this thesis. The content consists of following two parts. In part one, we fabricated some electrodes modified with the cabon nano material and use them as electrochemical sensors to catalyse some biological substance: (1) A partially reduced C60 film modified electrode was fabricated. In addition, the application of the modified electrode for the determination of NO was evaluated by cyclic voltammetry and amperomerty experiments. The results showed the modified electrode can catalyse the electroxidation of NO with good sensitivity and rapid response. (2) The acid-treated MWNT was cast on a gold electrode to form a MWNT film modified electrode. The experiments showed that the modified electrode had excellent characteristics for the selective determination of dopamine (DA) in the presence of ascorbic acid (AA) at the oxidative potentials with good sensitivity and selectivity. (3) we demonstrated the feasibility of forming Au/C₆₀ and Pt/C60 particles on glassy carbon electrodes by electrochemical method, respectively. In addition, we investigated the electrochemical response of DA at these modified electrodes and the experiment results showed the proposed electrode materials exhibited an excellent electrocatalytic activity for the determination of DA. The interference of AA can be efficiently eliminated at these modified electrodes. In part two, we studied the carbon nano materials as an optical probe to determine some proteins: A water-soluble C₆₀ derivative called fullerol was synthesized through the reaction of fullerene C₆₀ with NaOH in aqueous solution by means of ultrasonic agitation. Using resonance light scattering (RLS) technique, the interaction of fullerol with proteins was investigated. Based on the enhancement of RLS, a sensitive method for the determination of proteins has been established. On the other hand, this investigation also shows the potential application of fullerene derivatives in the biological field.