| The performance of sensing material determines performance of sensors. In this thesis, we use sol-gel method to prepare a new kind of multifunctional fiber optic biosensing materials that have the performance of enzyme catalysis and photo-sensitive synchronously. We determined the best immobilization method, preparation technology, and studied the possible influencing factors. The multifunctional fiber optic biosensing materials were detected by uv-spectrophotometer and lock-in phase amplifying technology. The immobilized effect of multifunctional sensing material was studied. We prepared the sensing probe by using multifunctional sensing material and realized the detection of different concentration of glucose solution. The influences of the immobilization method and preparation technology to the performance of fiber optic glucose sensor based on multifunctional sensing material were studied, which will be very helpful for improving the detection precision and stability, shortening the response time, simplifying the technological process .The main results are as follows:(1) Using TEOS as the main material, formamide as the drying control chemical additive, and using a closed and aging method, the sol-gel multifunctional fiber optic sensing material that immobilized glucose oxidase(GOD) and optical indicator(Ru(bpy)3Cl2) was developed. The influences of the solution components, drying rate, substrate to the properties of sensing materials were studied.(2) The influences of the formamide content for the performance of film forming, structure and the performance of sensitive membrane were studied, and the best amount of formamide added for preparing sensitive material was determined to be 3%.(3) The characteristics of free enzyme and multifunctional fiber optic biosensing materials were studied, including standard catalysis curve, the best catalysis temperature, the best catalysis pH, storage stability and operational stability and embedding stability. It was found that, for the free enzyme, the best catalysis pH was 5.5 and best catalysis temperature was 35℃. For the multifunctional fiber optic biosensing materials, the best catalysis pH and temperature were 6.8 and 40℃, respectively. The storage stability and operational stability of multifunctional fiber optic biosensing materials were better than those of free enzyme.(4) The influences of the fluorescence indicator concentration and pH to multifunctional sensing material were studied. It was found that the best indicator concentration was 1 mg/mL, and the best condition of pH was 7.0.(5) The fiber optic glucose sensor based on multifunctional sensing materials was fabricated and its sensing characteristics such as response time, detection range, reliability and repeatability were studied. The results showed that the fiber optic glucose biosensor had the linear detection range of 100-700 mg/dL, response time of less than 30 s, and better long-term stability. |
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