Construction Of Halogen Perovskite QDs Fluorescence Sensor And The Research Of Its Detection Performance Of Tetracycline

Tetracycline antibiotics（Tetracycline antibiotics,TCs）are one of the most widely used antibiotics in the world due to their good stability and high cost performance,They have been detected in the environment many times and have caused serious impacts on human health and the ecological environment.The traditional detection method is cumbersome to operate,long detection time,and high cost.The fluorescence analysis method based on quantum dots has the advantages of simple operation,rapid response,and low detection limit,and is widely used to detect various targets.However,the quantum yield of traditional quantum dots is low,and the sensitivity of fluorescent sensors prepared after surface modification is low.The new halogen perovskite quantum dots combine the advantages of halide perovskite and fluorescent quantum dots,exhibiting 90%luminous efficiency,narrow fluorescence half-width and adjustable fluorescence emission.Even after surface modification,it is better than most traditional quantum dots.However,halogen perovskite quantum dots have strong ionicity and are easily affected by solvents to cause fluorescence quenching,which is the main obstacle to their development and application in the field of fluorescence detection.In this paper,all-inorganic halogen perovskite quantum dots（IPQDs）are used as the basic fluorescent materials,and they are functionally modified to obtain three different perovskite quantum dot fluorescent sensors,which effectively improves the stability of IPQDs and can be stably dispersed in polar sovents（ethanol,water）to specifically detect trace amounts of tetracycline（TC）in the environment.It breaks through the limitation that the perovskite quantum dot fluorescence sensor can only be used in non-polar solvents.A variety of characterization methods were used to analyze the morphology,structure and fluorescence performance of the obtained fluorescence sensor to determine the best detection conditions.And the quantitative detection and selective recognition performance of three perovskite quantum dot fluorescence sensors for TC were studied.And the detection mechanism of its specific recognition of TC is discussed in detail.The main research contents of this paper are as follows:（1）3-Aminopropyltriethoxysilane（APTES）and oleic acid（OA）are used as ligands to prepare perovskite quantum dot fluorescence sensors（APTES@IPQDs）by supersaturated recrystallization at room temperature,it can be stably distributed in ethanol and can be used for fluorescence detection of tetracycline.At the same time,a variety of characterization methods were used to explore the morphological and structural characteristics of APTES@IPQDs.And we separately analyzed the influence of different polar solvents,stability,detection time and other factors on the fluorescence sensor,and obtained the best detection conditions.Furthermore,the detection ability of APTES@IPQDs for TC and its recognition mechanism were investigated through fluorescence detection experiments.The fluorescence detection of TC in the soil samples by APTES@IPQDs was successfully realized.（2）The porous SiO₂ with super large pore size（LMSNs）was selected as the carrier,and the water-soluble perovskite quantum dots were prepared by the aqueous emulsion method,and IPQDs were fixed on the surface of LMSNs by APTES to synthesize LMSNs@IPQDs perovskite quantum dot fluorescence sensor which can be stably dispersed in water and used for fluorescence detection of trace tetracycline in water environment.The morphology and structure characteristics of LMSNs@IPQDs composite materials were analyzed by a variety of characterization methods.The effects of factors such as pH,stability,and detection time have been studied respectively,and the best detection conditions have been obtained.Furthermore,the detection ability of LMSNs@IPQDs for TC and its recognition mechanism were investigated through fluorescence detection experiments.Finally,through the addition and recovery experiment of Weihe water samples,the fluorescence detection of TC in environmental samples by LMSNs@IPQDs was successfully realized.（3）SiO₂ nanoparticles was selected as the carrier,and the sol-gel method combined with Cetyltrimethylammonium Bromide（CTAB）as the pore former was used to prepare the silicon-based porous molecularly imprinted polymer.Using tetramethoxysilane（TMOS）to encapsulate the IPQDs on the porous structure and surface to synthesize the perovskite quantum dot molecularly imprinted fluorescence sensors（IPQDs@MIPs）which are used to fluorescently detect trace tetracyclines in water environments.The morphology and structure characteristics of the IPQDs@MIPs composite material were analyzed by a variety of characterization methods,and the effects of factors such as stability,pH and detection time were studied respectively,and the best detection conditions were obtained.Furthermore,the detection ability of IPQDs@MIPs on TC was investigated by fluorescence detection experiment.Selective comparison experiments show that IPQDs@MIPs can specifically recognize TC from a variety of tetracycline antibiotics.The established fluorescence detection method successfully realized the detection of TC in environmental samples.