Manufacture Of Novel Opto-chemical Sensors Based On Porphyrins And Preliminary Investigation On Piezoelectric Quartz Crystal Sensor Array

Due to the special activity of porphyrins, research efforts in analytical chemistry have been focused on these compounds. More and more analytical chemists tried to combine the TPP with other functional molecules to obtain the analytical reagents with high sensitivity. Recently there are of great interests in chemical sensors based on energy transfer because of its higher sensitivity and large Stoks movement. It is interesting to synthesize some porphyrin compounds bearing the groups, which can transfer energy with porphyrins and develop them as chemical sensors to detect some substances in micro-level.A single sensor with a selective coating material performs not so well in measuring the real complex gases. It is an effective way to solve this problem by combining piezoelectric quartz crystal sensor array with chemometrics. However, there were few reports in designing electric circuit, which would influence the response due to mutually interfering between oscillators. So, it is necessary to design a vibration circuit and develop it into small and convenient instrumentation to overcome this limitation.This thesis is mainly centered on the following two research aspects: 1) synthesizing six kinds of porphyrins containing different functional groups and applying them to analytical chemistry respectively. Based on the principle of energy transfer, a series of optical chemical sensors have been developed and applied to food examination, environment monitoring by detecting inorganic ions, inorganic neutral molecules and toxic organic neutral molecules. 2) improving the electric circuit of PQC sensors , then designing and assembling PQC sensor array, which has been used to examine the mix gases. Details are presented in this thesis as follows:1. According to the principle of energy transfer, an opto-chemical sensor with higher sensitivity to detect picric acid by using the mixture of porphyrin dimer and anthracene as fluorescent carrier has been developed. Compared with the traditional chemical sensors, it has faster response time, better reproducibility and reversibility, wider measurement range and higher sensitivity. Moreover, the determination was not affected by pH in neutral and base solution and it was unnecessary to pretreat sampleby using an acid, which is easy to apply to actual sample analysis,2. Fluorescein and porphyrin have been linked by an alkyl chain, and been firstly used as a fluorescence carrier of opto-chemical sensors. Based on the principle of energy transfer, it examined the iodine in the aqueous solution with high sensitivity and wide detection range.3. In order to further improve the energy transfer efficiency and detective sensitivity, anthracene has been directly connected with porphyrin as a conjugate group, which greatly shorted the distance between both of these compounds. This compound was firstly used as a fluorescence carrier of chemical sensors to examine the toxic p-nitroaniline. Compared with conventional methods, this sensor has lower cost, wider detection range, higher sensitivity and selectivity, better reproducibility and reversibility.4. A series of porphyrins with the multiaromatic amino groups have been synthesized and used as a fluorescence carrier to manufacture a pH opto-chemical sensor, which has higher sensitivity and wider response range.5. An optimized piezoelectric quartz crystal sensor array has been designed and assembled by using five individual vibration electrical circuits. Five different coating materials and four different toxic organic vapors (methanol, 1,2- dichloroethane, benzene and cyclohexane) have been selected as detective model to examine the feasibility of this instrument.