Studies On The Preparation And Sensing Properties Of Fluorescent Films Based On Photo-induced Electron Transfer

The design of fluorescent chemosensors as potential molecular devices has become one of the active research fields in chemical science during the past decades. Fluorescence techniques are widely used in biophysics, biochemistry, clinical chemistry and environmental science due to their high sensitivity and selectivity. Most fluorescence techniques have been used as sensors. The sensing is mainly based on the response of fluorescent probes or labels to the properties of tested solutions or systems. The probes and/or labels, generally speaking, cannot be reused for further measurement. Surface-oriented fluorescent sensor, through immobilization of a fluorescent molecule on solid substrates like silica or quartz, can provide more advantages over fluorescent probes used only in solution, such as reusing ability.In the past few years, a number of functional films with pyrene (Py) and dansyl as sensing elements that are quite sensitive to the microenvironment around them have been prepared and studied in our laboratory. These fluorescent films show remarkable sensing properties to the presence of nitromethane in methanol or water, sodium nitrite, dicarboxylic acids, and nitrobenzene in water.Fluorescent chemosensors by employing the phenomenon of photo-induced electron transfer (PET) can be used as sensors to monitor pH of solutions. However, most of the research work has focused on the design and preparation of fluorescent probes used only in solution, and very little work has been done about designing and preparing fluorescent film sensors for pH measurement. Therefore, design and preparation of this kind of film sensors is worthwhile. Based on the works of our group mentioned above, phenomenon of PET was introduced into the preparation of some novel film sensors.Anthracene and its derivatives are widely-used fluorophores in designing fluorescent sensors involving PET, and they exhibit a high potential as sensors for organic and inorganic analytes and as probes in life science and chemical science. Based on the above characters of anthracence and by introducing imino unites into spacers, several novel fluorescent film sensors exhibiting PET properties have been prepared. Furthermore, the photophysical behaviors and sensing properties of the films have been...