Fluorescence Detection And Degradation Properties Of Functional Metal-organic Frameworks Towards Antibiotics

Antibiotics have been extensively used in treating bacterial infections,and the antibiotic residues might cause potential hazards to humans and wildlife.Hence,it is extremely urgent to develop reliable and efficient methods to detect or eliminate residual antibiotics.As a new type of porous hybrid crystalline materials,metal organic frameworks（MOFs）have shown potential applications in gas adsorption and separation,catalysis and photocatalysis,fluorescence sensing,drug delivery and so on.In this thesis,the research work covers two main parts:I.A dual-emitting RhB@Zn-1 composite was fabricated and used as a recyclable fluorescence sensor for sensitive and selective detection of nitrofuran antibiotics;II.A ternary heterojunction Fe₂O₃@CN@NU66 was synthesized and utilized as an efficient photocatalyst for tetracycline degradation under visible light irradiation.The main contents of this paper are as follows:1.Synthesis and sensing properties of a dual-emitting RhB@Zn-1 composite.A dual-emitting RhB@Zn-1 composite was fabricated through modification of an ionic porous framework Zn-MOF with a cationic dye Rhodamine B via an ion-exchange process.Additionally,RhB@Zn-1 can serve as an efficient fluorescence sensor for sensitive and selective detection of nitrofuran antibiotics（nitrofurantoin and nitrofurazone）,with high K_SV values(5.61×10⁴ M^-1 and 4.73×10⁴ M^-1)and low detection limits（0.73μΜand 0.86μΜ）.Further studies reveal that the fluorescence quenching process might be ascribed to the synergistic effect of competitive absorption and photo-induced electron transfer mechanisms.2.Synthesis and properties of a ternary heterojunction Fe₂O₃@CN@NU66.A ternary heterojunction Fe₂O₃@CN@NU66 was successfully synthesized via a two-step synthetic strategy,and was characterized by XRD,FTIR,XPS,SEM,UV-vis DRS and PL.The composites exhibited excellent photodegradation efficiency for TC under visible light irradiation.Further studies showed that the photodegradation efficiency was also influenced by the dosage of the photocatalyst,TC concentrations,p H of the solution,et al.Moreover,the degradation process and the mechanism are proposed through the capture experiment and the Mott-Schottky curve.