Research On Kinetics Of Biochemical Process In Bacteria And Biology Using Electroanalytical Techniques

Because piezoelectric quartz crystal sensor has special advantages such as high sensitivity, broad sensing-spectrum, simple construction and low cost, it has been applied to numerous fields, including analytical chemistry, biochemistry, environmental monitoring, life science and molecular biology. The electrochemical techniques, especially stripping voltammetry, due to their high sensitivity, ease of application, low cost, high selectivity and accuracy, are widely used in the trace analysis of metal ions. Based on the response of piezoelectric bulk acoustic sensor to the viscosity and density of the solution and the high sensitivity of stripping voltammetry for the determination of trace metal ions, this thesis presents theoretical and applied studies for biochemical kinetic process of microbe and biology in several new systems as follows:1. The antimutagenic kinetic characteristics of Tea Polyphenols (TP) during the Salmonella typhimurium strain TA100 growth process in the presence of mutagen 4-methylnitrosamino-1-(3-pyridyl)-1-butanone (NNK) was studied with the piezoelectric impedance analysis technique, based on the variation of viscosity and density in the solution during the growth of bacteria. According to the relationship between the amount of TP and growth kinetic parameters (A,μm,λ), a new impedance response model reflecting this inhibition effect of TP towards NNK in TA100 solution was derived for the first time.2. A novel method for the simultaneous determination of cadmium (II) and copper (II) during the adsorption process onto the nonliving Pseudomonas aeruginosa was developed, as the concentration of the free metal ions can be detected by anodic stripping voltammetry on the mercaptoethane sulphonate (MES) modified gold electrode in the presence of macromolecules. Based on the electrochemical results, the kinetics and equilibrium of biosorption were studied. And the kinetic parameters and maximum adsorption capacity in the concomitant of the two metal ions and unaccompanied conditions were discussed by the non-linear fitting.3. The technique combined piezoelectric impedance analyzer with UV-vis spectrophotometer for the study of antibacterial kinetic process was proposed for the first time. The impedance response model for the bacterial growth and the metabolic kinetic model of TP were established. And the corresponding kinetic parameters were obtained by non-linear fitting. Moreover, the growth process kinetics of mixed culture of P. aeruginosa and S. aureus was also discussed.4. According to the changing of density/viscosity due to the HSA denaturalization and its renaturalization on the PQC sensor surface, the kinetics process of the urea-induced denaturalization of Human Serum Albumin (HSA) and its renaturalization with EDTA was studied by a HSA/Au nanoparticles/ 1,6-hexanedithiol modified PQC sensor. The piezoelectric response model for the binding was theoretically derived and the kinetic parameters can be gained by fitting the experimental data to the model.