Fluorescence Detector Based On MOF Conditions For Specific Recognition Of Tetracycline Antibiotics

The environment and human health are being adversely affected by antibiotic residues in soil and surface water.Therefore,there is an urgent need for convenient methods and reliable probes for the detection of tetracycline antibiotic residues.Among them,metal-organic frameworks,as emerging hot frontier materials,have the coordination entities and void coordination compounds.In addition to potential applications in gas storage,separation,catalysis,also include the direction of fluorescence detection.The system constructed in this paper is based on the specific recognition of tetracycline antibiotics by MOF fluorescence.Firstly,tetracycline antibiotics are used as the target molecule,and the MOF probe synthesized by hydrothermal method is used as a fluorescence sensor.The concentration,stability and response time of the MOF probe are studied using a fluorometer to determine the best detection method for tetracycline antibiotics condition.Establish the detection mechanism of tetracycline antibiotics through specific identification and quantitative detection results.And with the help of TEM,FTIR,UV,XRD to explore the probe morphology,structure and optical properties to improve the entire detection theory.The main research results are as follows:In Chapter 1,we briefly describe the general situation of tetracycline antibiotics,and analyze their availability,harm and detection methods.According to domestic and foreign literature,the research progress of MOF materials and fluorescent probes is introduced,which confirms the theoretical and practical of this topic.Focus on the research progress and results in this field,and in-depth exploration of the deficiencies of existing research and topics worthy of extension.At the same time,the main research content of this thesis is sorted out with experimental research as the center.In Chapter 2,an Europium-modified zeolite imidazole skeleton(ZIF-Eu)is used to sensitively and selectively detect trace amounts of doxycycline(DOX).Detected by the chemical coordination between DOX and Eu on the surface of ZIF-Eu,the probe ZIF-Eu and different concentrations of DOX show a significant ratio of fluorescence changes,generating new fluorescence emission at 615 nm,but still retain the original emission at 420 nm,which changes the visible fluorescent color from green to red.The detection limit in the buffer solution was determined to be 49 nM,which is sufficient for the detection of lower concentrations of contaminants.In addition,the use of probe ZIF-Eu has achieved in-situ detection of trace DOX pollutants in soil through solid-state compression,which shows its great potential in practical applications.In Chapter 3,ZnO and 5-aminoisophthalic acid are used to synthesize modified metal organic framework probes with-NH2,-H and-COOH functional groups[Zn/H2aip].Based on the above,the ratio detection of the tetracycline family(TCs:TC,OTC,DOX and CTC)is proposed.Among them,the probe itself does not show strong fluorescence.In the presence of different kinds of tetracyclines,the fluorescence of the probe[Zn/H2aip]is quenched at 403 nm,and at the same time at 517 nm(adding TC)and 525 nm(adding OTC)),513 nm(DOX added),520 nm(CTC added)produce strong emission peaks.It relies on the identification of specific peak positions of TC,OTC,DOX and CTC,and shows excellent performance in qualitative analysis.Subsequently,this paper will focus on the use of fluorescence integration method to quantify the degree of contamination of tetracycline antibiotics through the "TCs Analysis" application,which is not limited to identifying individual antibiotic.Fluorescence integration method is a new method to measure the degree of pollution,through rigorous data analysis and intelligent processing,and is suitable for portable detection.In Chapter 4,a new application of oxytetracycline(OTC)as a fluorescent probe is proposed,which proves that it can provide a rapid,highly sensitive and selective detection method for Ca2+.The addition of Ca2+ can significantly enhance the fluorescence of OTC,with fast response and high sensitivity,and the detection limit in aqueous solution is as low as 125 nM.The coordination of the complex formed by Ca2+ with the hydroxyl group of OTC is helpful for fluorescence enhancement,which is proved by characterization methods such as ultraviolet-visible analysis,binding constant determination and fluorescence titration.This method combines usability,stability and operability to avoid the complexity of EDTA measuring Ca2+ in water,and can be successfully applied to Ca2+ detection in actual environments.