Synthesis And Characterization Of Fluorescent Chemical Sensors Of Oxadiazole And Naphthalene

Chemical fluorescent sensors are simple, convenient, fast and able to implement real-time testing, so it has been widely used to the environmental detection, and biochemical detection of heavy metal ions. Now the trend of chemical sensor is to have high selectivity, sensitivity, specificity and the sensitivity to be more compact and efficient. They facilitate the subsequent application of real-time online detection. Now the chemical fluorescent sensors are also widely used in military practice, science and production. Therefore, the sensitivity of high-end developed chemical sensors has a very important practical value.This paper illustrates the design and synthesis of two different fluorescent sensor of the two different fluorophores:one of containing oxadiazole groups and another is containing naphthalene group of sensor, both sensors' receptor is di-(2-picolyl)amine. This receptor has an excellent recognition performance, and it was widely used by a lot of chemists as a sensor of receptor.The first chapter is divided into two parts, the first part deals with a brief introduction, the background and the definition of chemical sensors and their application space and prospects. Principles of chemical sensors in this part majorly introduce photo-induced electron transfer types of sensors, because the two sensors in this paper are types of photo-induced electron transfer sensors. photo-induced electron transfer sensor has many advantages; it can play a controlling role like a switch, which can be a good application to the original in the sense of light. Some sensors play an important role in a fluorescence enhancement and fluorescence quenching, that whether it is enhancing or quenching, it changes the process like a switch; the fluorescence enhancement is related to the opening and fluorescence quenching is related to switching from ON to OFF. The second part focuses on nearly two decades of chemical sensor research. In the last two decades, chemical fluorescent sensors research has made great progress. Researching for specificity and regeneration of sensors has great progress. Many of the sensors are not a renewable in the early studies, but the regeneration of the sensor has been improved so much in recent years of the study, so that it come up to today's green chemistry requirements.The third chapter describes the design and synthesis of own containing 1,3,4-oxadiazole chemical sensor. The sensor was synthesized by two methods, one of the methods is fractional steps synthesis, and another is one step method synthesis. The initial raw material for both methods is o-methyl benzoic acid. One step method is simple and saving raw materials with high yield advantages. The sensors in acetonitrile and water with volume ratio of 4:1 which show a good selectivity in the solution of copper ions, but when in the detection selectivity of anions which did not have a good selectivity, we can see that this sensor can only be used as the metal cation sensor which cannot serve as anion sensors.The main content of the forth chapter contains the synthesis and investigation of the properties of this chemical sensor of naphthalene. The sensor was synthesized in this chapter by the 1,8-naphthalene diamine starting after only two steps to the final. Synthesis of the sensor, a short synthetic route of this experiment is simple. When testing the selectivity of this sensor, we found that the sensor is still selective for copper ions, the fluorescence intensity can increase to 4 times, and by measuring the titration curve of this sensor, we can see the sensor and the copper ion complexation ratio of 1:2, fluorescence intensity of this sensor can be strengthened with added up the copper ions.