Synthesis And Application Of Enzyme-free Sensors Based On Rigid Chain Liquid Crystaline Polymers Contained Ferrocene

In this thesis, we have designed and synthesized a series of rigid chain liquid crystalline homopolymers(PFECS) and amphiphilic block copolymer(PEO-b-PFECS) based on ferrocene. Then we focused on their liquid crystalline behavior and electrochemical behaviors, and we investigated the effect of the liquid crystalline behavior of PFECS on the electrochemical catalytic hydrogen peroxide.Furthermore, we found that the polymer and carbon nanomaterials composite could improve the electrochemical catalytic property of sensor. The main topics of this paper are as follows:1. A series of ferrocene-based rigid chain liquid crystalline homopolymers: poly{2,5-bis [(2-ferroceneylethyl)oxy carbonyl]styrene}(PFECS) and a series of ferrocene-based diblock copolymers PEO-b-PFECS, were successfully synthesized.The molecular characterizations of the homopolymers and diblock copolymers were performed with 1H NMR.The phase structures and thermostability of the polymers were investigated by thermogracimetric analysis(TGA), differential scanning calorimetry(DSC) and polarized optical microscopy(POM). The surface morphology and electrochemical behavior of the composite film was demonstrated by scanning electron microscope(SEM), electrochemical impedance spectroscopy(EIS) and cyclic voltammetry(CV).2. The experimental results showed that the electrode modified by PFECS and the PEO-b-PFECS e could be used for direct electrocatalysis detection of H2O2. Their electrochemical performance was depended on the molecular weight of the polymer.After annealing process, the direct electron transfer between PFECS and electrode surfaced was weakened. In the case of PEO-b-PFECS the same phenomena has been investigated. We speculated that the average spacing between adjacent ferrocene moieties became larger than that of the ferrocene moiety before annealing. Thus, it is necessary to adjust the spacing of the adjacent ferrocene moieties for electron self-exchange reaction. On the contrast, the liquid crystalline homopolymer PFECS-5has higher sensitivity than that of the PFECS-1 without liquid crystalline property for.electrocatalysis detection of H2O2. After annealing, the electrode modified PEO-b-PFECS-3 for electrocatalysis detection of H2O2 was reduced.3. The sensor based on polymers film and carbon nanomaterials show a wider detection range, higher sensitivity for H2O2 detection than the electrode modifiedpolymers film. Furthermore, the direct electrochemistry of composite film is a quasi reversible process of surface control.