Supramolecular Assembly In Biosensor Applications

With the development of life science, there has been increasing interest in biosensor in recent years. Amphiphilic organic molecules can be assembled into order and layer number-controlled thin films. These thin films exhibit physical properties different from those bulk crystals and per molecule. In particular, when some functional biomolecule was imbedded by way of covalence or noncovalence on the surface of the films, the films have many functions of biological membrane. These functions made supramolecular assembly technology have important application prospects. In this thesis diacetylene and its mannose derivative were polymerized by UV-lamp. Thus the blue film of polydiacetylene and its mannose derivative were got and UV-vis, RRS, FTIR,and CV were used to study the changes of these films when these films were incubated with E.coliK12. The details of the article are as follows:The preparation of diacetylene and its mannose derivative monolayers: We successfully prepared the monolayers of diacetylene and its mannose derivative on the water surface by the KSV-5000 trough. π-A isotherms showed that diacetylene and its mannose derivative were misible. On the basis of it, π-A isotherms were analyzed at different PH, temperature,molar fraction of MPDA and the optimal condition were obtainedThe preparation of polydiacetylene monolayers and the studies of its spectroscopic properties: The MPDA/PDA monolayers were irritated by 254nm UV-lamp for 20 seconds and the sensitive monolayers were produced.The UV-vis spectra showed that the recognition between mannose and E.coliK12 is specific .The results of the RRS confirmed that the bands of double and triple bonds simultaneously shifted toward high wavenumber and its electrical structure of the backbone changed from acetylene to butatriene. Furthermore, through comparing with the changes of FTIR and RR spectroscopy during the therochromism and affinochromism we concluded that the same changes of backbone structure was produced during the therochromism and affinochromism.The preparation of gold electrode of double layers and the spectroscopic and electrochemical studies when it was incubated with bacteria: CV measurement demonstrated that the defect content within the double layer gradually decreased during the incubation, SERS showed that the film structure became order during the incubation and the bands of double and triple bonds shifted toward high wavenumber, too.The organized assemble of the CdS nanoparticles on the surface of the polydiacetylene film and its influence on the polydiacetylene film: The results of UV-vis spectra showed that when CdS nanoparticles were assembled on the surface of the polydiacetylene film, the changing speed of CR became fast. The results of RRS demonstrated CdS nanoparticles have no influence on the double and triple bonds. The photoluminous measurement showed that CdS nanoparticles caused the luminous bands become weak and the red shift.