Applications Of Functional Polymer Material In Analysis Of Environment And Biosensor

Owing to the unique structure,electronics,machanical and optical properties, Nation film and polythiophene derivative as functional polymer materials have been wildly used in the fields of modification of electrodes,sensors and biology since their discovery.In the thesis,Ag-NCs on Nation film were prepared in the mediation of ATP and a visual method for formaldehyde was further developed based on the color change on Nation film.In addition,new analytical methods for spermine and temperature were proposed based on the flexible conformation of polythiophene derivatives(PT).The main contents are as follows:(1) Nation film could be saturated with[Ag(NH₃)₂]⁺ when incubated in silver ammonia solution.It was found that the Nation film if immerged into the formaldehyde solution became yellow and monodisperse Ag-NCs formed on the film in the presence of ATP.The Ag-NCs on Nation film were characterized by SEM,X-ray,plasmon resonance light scattering and dark-field light scattering.We supposed that ATP acting as a mediator through the interaction of the[Ag(NH₃)₂]⁺ with the aza group of ATP control the shape of nanoparticles and immobilized the nanoparticles on film.In addition,with the color change on the Nation film,a novel visual method for formaldehyde was developed,giving a sensitive detection of formaldehyde with a limit of determination of 60 ppb(3σ).(2) Polythiophene derivative bond to ctDNA could effectively resist iodide-induced aggregation in weak acid.With the addition of spermine,it could selectively interact with ctDNA so that ctDNA couldn't bind to PT.Then the PT aggregated in the addition of iodide,accompanying color and optical properties change.With that,a new colorimetric and fluorometfic method for spermine was developed with a limit of determination of 1.2μM(3σ).(3) It was known that the natural PT gave no response for temperature. Iodide-induced PT,however,was found to exhibit thermoresponsive behavior.At room temperature of 25℃,the iodide-induced PT showed red color and very weak fluorescence.With the temperature increased to 55℃,the aggregates of iodide-induced PT were disrupted,resulting in red to yellow color change and the fluorescence recovery. Therefore,a temperature sensor showing a colorful change in color and fluorescence in the temperature range 25℃-55℃could be developed based on iodide-induced PT.