Synthesis Of Functional Fullerene Derivatives And Their Application In Electrochemical Detection Of Active Ingredients In Chinese Herbal Medicine

C60 and its derivatives have attracted much attention from different researchers domestic and foreign, due to their excellent spatial structure. In order to expand the physical and chemical properties of C60 and its application, C60 has been chemically functionalized by various methods and different groups were attached on its globular framework. [2+3] cycloaddition reaction has been an important method for C60 chemically modified, because it can generate single bonus C60 pyrrolidine derivative, and such synthetic method is simple,the product is stable and less by product. In this dissertation, three novel fullerene derivatives were synthesized by C60 [2+3] cycloadditional reaction and hydroxylated reaction and applied to the electrochemical highly sensitive detection of Chinese herbal active ingredient quercetin and chlorogenic acid. The definite contents are as follows:(1) With benzaldehyde and L-tryptophan as materials, which reacted with C60 through the [2+3] cycloaddition, two isomers [60] Fulleropyrrolidines were synthesized. The crude products were separated by silica gel column and further purified by prepared liquid chromatography, then two 2-phenyl-5-(1-indole methyl) C60 fullerene pyrrolidinederivatives(namely C60-SE1 and C60-SE2) were obtained separately. The two products were characterized by proton nuclear magnetic resonance spectrum(1HNMR), mass spectrometr(MSn, n=1, 2), Fourier transform infrared spectroscopy(FTIR), ultraviolet visible spectroscopy(UV-Vis) and fluorescence spectroscopy(FLS) to determine their structures and spectral properties.(2) With terephthalaldehyde and L-serine as materials, which reacted with C60 through the same [2+3] cycloaddition, 2-(4-formylphenyl)-5-(1-hydroxyl methyl) [60] Fulleropyrrolidines was synthesized. The crude products were separated by silica gel column and further purified by prepared liquid chromatography with different separation and purification conditions. The product was characterized by 1HNMR, MSn(n=1, 2), FTIR and UV-Vis, and FLS to determine its structure and spectral propertie. The formula of the product was C70H11NO2 and its yield was 38.04%.(3) Product C60-SE1 was immobilized on the surface of glassy carbon electrode(GCE) by the direct coating method and the modified electrode C60-SE1/GCE was obtained. Using [Fe(CN)6]3-/4- as a probe, GCE, C60/GCE and C60-SE1/GCE were characterized by cyclic voltammetry(CV) and electrochemical impedance spectra(EIS). The results showed that C60-SE1/GCE had excellent conductivity. The modified electrode(C60-SE1/GCE) was further utilized as a sensor model for sensitive detect quercetin with phosphate butter(PBS) as the buffer solution, using CV and differential pulse voltammetry(DPV) technology to detect quercetin. The experimental results showed that a pair of well-defined redox peaks appeared on the C60-SE1/GCE. The optimized conditions for detection quercetin: the amount of C60-SE1 was 5.0 μL, the p H of PBS buffer solution was 3.0. Under the best conditions, the peak currents of quercetin with their concentrations presented a good linear relationship in the range from 1.0×10-8 mol/L to 6.0×10-6 mol/L, with a detection limit of 6.1×10-9 mol/L(S/N=3).(4) A novel nanocomposite(FC-GO) consisted of water-soluble C60 hydroxyl derivative-fullerenols(FC) and graphene oxide(GO) was synthesized through simple ultrasonication with a certain percentage of quality. The nanocomposite’s microstructure was characterized by scanning electron microscope(SEM), and then the nanocomposite was cast on a GCE to get a new modified electrode(FC-GO/CS/GCE) with the help of chitosan(CS) film. Using [Fe(CN)6]3-/4- as a probe, GCE, CS/GCE, FC/CS/GCE and FC-GO/CS/GCE were characterized by CV and EIS. The results showed that FC-GO/CS/GCE has wonderful conductivity. The modified electrode(FC-GO/CS/GCE) was further employed as a sensor model for sensitive detect chlorogenic acid by CV and DPV with PBS as the buffer solution, and a pair of well-defined redox peaks appeared. The optimized conditions: the quality proportion of FC and GO was 1:5; the p H of PBS buffer solution was 2.5. Under optimal conditions, the peak currents of chlorogenic acid with their concentrations presented a good linear relationship in the range from 5.0×10-8 mol/L to 1.1×10-5 mol/L, with a detection limit of 4.6×10-9 mol/L(S/N=3).