| Chemical modification is one of the most important research fields in the fullerene research. It is significance to synthesize fullerene derivatives owning special properties and functions by fullerene chemical modification in expansion the fields of fullerene research. Among these functionalization methods, 1,3-dipolar cycloaddition and hydroxylation of fullerene have been wildly used to synthesize many functionalized fullerene derivatives. This dissertation focuses on the researches on the synthesis, separation and characterization of C60 derivatives and their applications in DNA electrochemical sensors. Main contents are as follows:Two isomers of fulleropyrrolidine, named 2-(4-formylphenyl)-5-(1-hydroxyethyl)- fulleropyrrolidine, were synthesized and separated by the reaction of C60 with threonine and terephthalaldehyde in the method of the 1, 3-dipolar cycloaddition, marked as C60-CHO I and C60-CHO II, respectively. The products were characterized by FTIR, 1HNMR, MSn (n=1, 2, 3) and UV-Vis, and their chemical formulas were C71H13NO2. The optical and electrochemical properties of the derivatives were determined by fluorescence and differential pulse voltammetry.One of fulleropyrrolidine, C60-CHO I, was used as a platform for covalent immobilization of probe DNA through a facile amine-aldehyde condensation reaction to fabricate a novel DNA biosensor. The oligonucleotides related to CaMV35S promoter fragment were determined with the developed biosensor via electrochemical impedance spectroscopy using [Fe(CN)6]3?/4? as indicating probe with a line range of 1.0×10-13 1.0×10-9 mol/L and a detection limit of 1.5×10?14 mol/L. It also showed that the developed biosensor could display a good selectivity between the complementary ssDNA and mismatched ssDNA.The other fulleropyrrolidine, C60-CHO II, was coated on GCE electrode to covalently immobilize and hybrid probe DNA. Differential pulse voltammetry was used to the sensitive detection of the hybridization of DNA with methylene blue as the indicator. The oligonucleotides related to CaMV35S promoter fragment were monitored using this DNA electrochemical sensor with a linear range of 1.0×10-15 1.0×10-9 mol/L, and a detection limit of 4.0×10-16 mol/L. The present biosensor can effectively discriminate complementary from mismatched DNA sequences.Water-soluble fullerenol was prepared by the reaction of C60 with NaOH using tetrabutylammonium hydroxide (TBAH) as a phase transfer catalyst. A 3D platform based on fullerenol DNA electrochemical sensor was fabricated owning to the nano effect and active polyhydroxy of fullerenol. The DNA surface density was determined using a chronocoulometric method and the amount of DNA was 2.24×1013 (molecules/cm2). The target DNA sequences were determined by cyclic voltammetry and electrochemical impedance spectroscopy using [Fe(CN)6]3-/4- as indicating probe with a linear range of 1.0×10-15 1.0×10-9 mol/L. The detection limit was 1.7×10-16 mol/L. The successful discrimination between the complementary, three-base mismatched and non-complementary ssDNA displayed a good selectivity for the biosensor.
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