Fabrication Of Lanthanide Coordination Polymer And Their Applications In Sensing

Highly sensitive time-resolved fluorescence analysis techniques developed based on lanthanide-coordinated polymer probes with long fluorescence lifetime,large Stark shift and sharp emission peaks have been widely used in the field of biological monitoring.In the research of this master 's thesis,three kinds of rare earth complex fluorescent probes with specific identification and sensing function for some small molecular substances and ions were designed and synthesized respectively.Main research contents:(1)The water-soluble mercuric ion(Hg2+)is one of the most stable inorganic forms of mercury,which is non-biodegradable and bioaccumulable through the food chain.Even at very low concentrations,it can damage brain,kidneys,and nervous system.Lanthanide coordination polymers(LCPs)have recently emerged as attractive biosensor materials due to their flexible components,high tailorable properties and unique luminescence features.In this work,we designed a smart LCP probe of TbCIP/AMP {(CIP,ciprofloxacin)(AMP,adenosine monophosphate)} for Hg2+ detection by using lanthanide ions as metal nodes,CIP as ligand molecule,and AMP as bridging linker and recognition unit.Tb-CIP/AMP emits a strong green luminescence due to the inclusion of AMP,which withdraws the coordinated water molecules and shields Tb3+ from the quenching effect of O-H vibration in water molecules.The subsequent addition of Hg2+ into Tb-CIP/AMP can strongly quench the fluorescence because of the specific coordination interaction between AMP and Hg2+.As a kind of Hg2+ nanosensor,the probe exhibited excellent selectivity for Hg2+ and high sensitivity with detection limit of 0.16 n M.In addition,the probe has long fluorescence lifetime up to millisecond and has been applied to detect Hg2+ in drinking water and human urine samples with satisfactory results.We envision that our strategy,in the future,could be extended to the designation of other LCP-based hypersensitive time-gated luminescence assays in biological media and biomedical imaging.(2)The normal value of p H of human serum is 7.2,and the abnormality of p H is associated with many major diseases,such as cancer and Alzerimer's disease.Hence,designing an effective p H probe for biofluids are highly valuable for the diagnosis of some diseases.Lanthanide coordination polymers(LCPs)have emerged as fascinating materials because of their specific structure and properties.In this work,utilizing hydrosoluble biomolecule of guanosine-5'-monophosphate(GMP)as bridging linker,lanthanide terbium ions(Tb3+)as metal nodes,and silver ions(Ag+)as sensitizers,we synthesized a p H responsive luminescent lanthanide CP probe of Tb/GMP/Ag.The probe possesses high luminescence due to the sensitization of Ag+;While in alkaline solutions,Ag+ in Tb/GMP/Ag immediately binds to OH-,forming Ag2 O precipitation and resulting in a distinct fluorescence quenching of Tb/GMP/Ag.This probe displays high selectivity for OH-and a broader p H detection range of 7.5-13.0.In addition,based on the high anti-interference ability in serum,we applied Tb/GMP/Ag to measure p H in undiluted human serum samples,yielding satisfactory results.(3)Abuse of ciprofloxacin has a negative impact on humans,including gastrointestinal disorders,central nervous system disorders,skin sensitization and liver injury.Therefore,the highly sensitive analytical method,it has the ability to accurately and effectively determine the urgent requirements of these compounds in medicine.Metal organic coordination polymers(MOCPs)have emerged as a new family of functional nanomaterials.In this work,we report a facile and effective fluorescent method for detection of CIP in tablet utilizing one kind of lanthanide coordination polymer nanoparticles(LCPNs).Eu/GMP NPs as the sensing platform,which composed of guanosine monophosphate(GMP)and europium ion(Eu3+),is nonluminescent.However,the subsequent addition of CIP into the resulting Eu/GMP NPs enhanced the fluorescence distinctively due to the strong coordination interaction between CIP and Eu3+ and the hydrophobic interior environment which rendered efficiently the energy transfer from CIP to Eu3+.The variations of the fluorescence intensities of Eu/GMP at 615 nm show a linear relationship for CIP within the concentration range of 1.6-40 ?M with a detection limit of 780 n M.As a kind of nanosensors,we believe,the LCPNPs possess great potecntial in the applications of ultrasensitive time-resolved fluorometric assays.