Research On Biosensing Methods Based On Conjugated Polymer Nanoparticles And Carbon Nitride Nanosheets

Biological sensing technology is an emerging technology,it involves the knowledge of many subjects such as biology,chemistry,physics,medicine.And it has the advantages of high sensitivity,high speed and good selectivity,can be used for continuous detection in complex system.Because of its characteristics of miniaturization,automation and integration,it has been widely used in many fields such as environmental monitoring,food safety and biomedical application.Meanwhile,nanomaterials have got a lot of attention by researchers with their unique properties that are different from other materials.Scientists developed a new type of biosensor,improve the detection performance of the biological sensing,and promoted the rapid development of nanotechnology and biological sensing technology by combining biological sensing technology and nanomaterials.This paper combines the unique properties of the conjugated polymer nanoparticles and carbon nitride nanosheet,choosing one of the widespread pollutants in environment(hydroquinone,2,4,6-trinitrotoluene)as the research object,established a series of new nano sensing methods for pollutants analysis.Hydroquinone is a contaminant which comes from industrial production,it causes damage to the environment and it is also a potential carcinogen,which may seriously affect the central nervous system.2,4,6-trinitrotoluene has always been used as explosives.Nowadays in many studies of environmental problems such as forensic research and mine detection,the analysis of 2,4,6-trinitrotoluene has aroused people's interest.In the long-term process of testing,using,storing and dumping,2,4,6-trinitrotoluene has accumulated in natural water,polluted the environment,and posed a threat to human and wildlife health.Due to the fact that hydroquinone and 2,4,6-trinitrotoluene are toxic to the environment and humans,it is necessary to develop a high sensitivity and selective method to detect hydroquinone.Compared with traditional methods,the method of biosensor analysis is simple,sensitive and selective.The specific contents are summarized as follows:In chapter 2,we set up a new type of conjugated polymer nanoparticles based on PFBT and used it in the ratio-dependent fluorescent probe strategy.This method is simple to operate and can achieve high sensitive and selective detection for hydroquinone.The method is depending on the oxidation product(benzoquinone)of hydroquinone and its quenching of CPNs fluorescence.Benzoquinone is an effective quenching agent of fluorescence because of its rich electronic conjugated structure.The fluorescence quenching degree is related to the concentration of hydroquinone,CPNs was used in fluorescence probe and catalyze the oxidation of hydroquinone to benzoquinone.The detection method we proposed is simple and stable,and can be used in the same kind solution system.In chapter 3,We have designed a fluorescent probe based on g-C3N4 nanosheet,this method has the advantage of simple operation and it is able to analyze 2,4,6-trinitromethylbenzene sensitively and selectively.We speculated that due to the benzene ring structure of 2,4,6-trinitromethylbenzene,it will combine with g-C3N4 nanosheet by the interaction of electrostatic effect and ?-? accumulation,so that the fluorescence peak value of g-C3N4 nanosheet dropped significantly.The fluorescence quenching degree is associated with the concentration of 2,4,6-trinitromethylbenzene.The method is simple and stable,and it can also be applied to the actual environmental water detection.