The Studies And Applications Of Novel Chemically Modified Electrode And Magnetohydrodynamics In Stripping Voltammetry

The fabrication of chemistry sensor is one of the most interesting fields of analytical chemistry. Especially, the application of nano-materials and self-assembled monolayer are distinguished. On the other hand, the magnetohydrodynamics (MHD) is always the focus in electrochemistry. In this thesis, gold nanoparticles and self-assembled monolayer doubly modified electrode were used for the stripping voltammetric determination of heavy metal ions in the complex samples. Multipulse potentiostatic electropolymerization was employed for the fabrication of carbon nanotubes/poly(1,2-diaminobenzene) nanoporous composite based electrode, which provided an excellent platform for the fabrication of ultra sensitive chem/biosensor. The magnetic field was used for the electroanalysis, then the sensitivity and reproducibility of the determination were obviously improved because of the MHD caused by the magnetic field. The creative works of this thesis are summarized as follows:1. A new method for the directly determination of Pb²⁺, Cu²⁺ and Hg²⁺ free from macromolecule interferences using a MES/gold nanoparticles doubly modified electrode was developed. Gold nanoparticles were applied for an improved sensitivity and the MES monolayer could effectively inhibit the macromolecules from reaching the electrode surface. The limits of detection were 0.1547, 0.1359 and 0.1341 ppb for Pb²⁺, Cu²⁺and Hg²⁺, respectively. The linear range was 1-100 ppb. The results of the method accorded well with those obtained by the atomic absorption spectrometry. The method was sensitive, accurate, credible, and has excellent reproducibility. It has a great potential for the practical analysis.2. Kinetic process of cadmium and copper competitively binding to human serum albumin (HSA) was studied on the MES/gold nanoparticles modified electrode with stripping voltammetry. The concentrations of free metal ions could be detected on the modified electrode in the binding process. A two-step consecutive model was derived to describe the binding process. The kinetic parameters of cadmium and copper binding to HSA were obtained by the non-linear fitting. The binding process could be real-time and quantitatively investigated.3. A novel method for the fabrication of carbon nanotubes/poly (1,2-diaminobenzene)...