| Life science, environmental science and materials science are dominating the21st century;all the basic studies and high-tech development area need the support of the analytical science,which brought forward new challenges to it. Electrochemical voltammetry has severaladvantages, such as the instrument is simple and suitable for constructing inexpensive andportable detectors, which aroses the researchers’ attentions. Carbon ionic liquid electrodesdue to their unique chemical and physical properties, such as good conductivity, highchemical and thermal stability, wide electrochemical windows etc., are widely used. In thisthesis, a series of studies on the development of novel modified carbon ionic electodes aschemosensors and their application in the analysis in environmental and biological area, andsome valuble results were obtained. The main points of this thesis are summarized as follows:1. Simultaneous determination of dihydroxybenzene isomers was investigated at aMCNTs/β-cyclodextrin composite modified carbon ionic liquid electrode in phosphate buffersolution （pH=-7.0） in the presence of cationic surfactant cetylpyridinium bromide （CPB）.With the great enhancement of surfactant CPB, the voltammetric responses ofdihydroxybenzene isomers were more sensitive and selective. The oxidation peak potential ofhydroquinone was about0.024V, catechol was about0.140V and resorcinol0.520V indifferential pulse voltammetric （DPV） measurements, which indicated that thedihydroxybenzene isomers could be separated entirely. The electrode showed wide linearbehaviors in the range of1.2×10-7～2.2×10-3，7.0×10-7～1.0×10-3，2.6×10-6～9×10-4mol·L-1for hydroquinone, catechol and resorcinol, respectively. And the detection limits of the threedihydroxybenzene isomers were4.0×10-8,8.0×10-8,9.0×10-7mol·L-1, respectively.2. A sensitive ascorbic acid （AA） sensor was fabricated by dropping the cationicsurfactant hexadecyl trimethyl ammonium bromide （CTAB） on the carbon ionic liquidelectrode. It was found that CTAB had an enhancement effect on the AA accumulation. Whenall the experiment conditions were optimized, the proposed sensor responds to AA linearlyover concentration range of4.0×10-7to6.4×104M with correlation a coefficient of0.98-7.The detection limit can be estimated for1.0×10-7M defined from a signal/noise ratio of3.The response time of the biosensor was fast （within8s）. The interference studies showed thatthe modified electrode exhibited excellent selectivity in the presence of dopamine （DA） with aconcentration of50-times higher than that of AA.3. An electrode was developed for the determination of hydrogen peroxide （H2O2）. Itcontained a chitosan copper complex onto which multi-wall carbon nanotubes in an ionicliquid were deposited. The modified electrode exhibited excellent electrocatalytic activity that was applied to the detection of H2O2. The pH value and the effect of electrical potential on thecurrent response were optimized. The electrode displays good stability, an expanded linearresponse range, improved electrocatalytic activity towards H2O2, and enables detection ofH2O2with a linear response from0.02to13.0mM of H2O2. The detection limit was1.0μM（at S/N=3）.4. A novel voltammetric sensor based on chemically modified bentonite–porphyrincarbon ionic liquid electrode has been introduced for the determination of trace amount ofMn（II）. In this method Mn（II） gave well-defined voltammetric peaks. The detection limit（three times signal-to-noise） was9.0×108mol·L-1. The peak currents increased linearly withthe concentration of Mn（II） over the range of1.0×10-7to5.0×104mol·L-1（R2=0.995）. |
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