The Preparation Of Fluorescent Probes Based On The Ratio Of Nanocomposites And The Study Of Fluorescent Visualization Detection

Nanomaterials belong to the material that has at least one dimension in the three-dimensional range with the nanometer scale.Due to their various synthetic methods,easy-functionalized surfuces,tunable emission wavelength,stable photochemical property,good biocompatibility and low toxicity,nanomaterials have received extensive attention in the academic community.As typical fluorescent nanomaterials,noble metal nanoclusters and carbon dots have many advantages,such as small synthetic particle sizes,stable photoluminescence,high quantum yields,strong fluorescence stability and low cytotoxicity,etc.They have broad prospects in the application fields for substance detection and chemical imaging.This work designed two novel detection systems for dual-signal ratiometric fluorescence probes,based on fluorescence resonance energy transfer?FRET?effects for the detection of biomolecules in actual samples.The main research contents are available as follows:?1?A ratiometric fluorescent probe based on AgNCs and Rhodamine 6G was designed to visualize melamine detection.AgNCs emitting blue fluorescence were prepared,and the maximum emission wavelength is 500 nm.A self-assembled complex of DNA-AgNC-Rh6G was synthesized by the interactions between Rhodamine 6G and DNA-AgNCs.When melamine was added,melamine combined with AgNCs through hydrogen bonding,which led to the decomposition of DNA-AgNC-Rh6G self-assembled complex.The fluorescence resonance energy transfer effect disappeared,which made the fluorescence enhancement of AgNCs.The fluorescence intensity of Rh6G at 570 nm was weakened.The probe exhibits a concentration range of melamine from 0.1 to 10?M and the detection limit is 25 nM.The method has high selectivity and sensitivity to melamine,and visual fluorescence detection in aqueous solution and on filter paper.?2?The ratiometric fluorescent probes Fe₃O₄@B-CDs@MIPs were constructed based on blue fluorescence carbon dots and Fe₃O₄ magnetic nanoparticles to detect phycoerythrin in the actual sample.The probes were constructed by molecularly imprinting technology,using the blue fluorescence emitting carbon dots and orange fluorescence emitting phycoerythrin.When phycoerythrin was added,the fluorescence resonance energy transfer effect occurred.The fluorescence of the blue carbon dots at 450 nm was slightly weakened and the fluorescence of phycoerythrin at 605 nm was gradually increased with the addition of phycoerythrin of different concentrations,which rapidly realized the detection of phycoerythrin.The linear detection range is 5²00 nM.The detection limit is about 1.6 nM.Simultaneously,the probe can be successfully applied to the determination of phycoerythrin in environmental water samples,together with high recoveries.