Research On The Preparation Of Nanoparticle Complex Ratio Fluorescent Probes And The Visual Detection Of Biomolecules

In the organism,some important molecules such as dopamine,ciprofloxacin,and tyrosinase,participate in various activities of human physiology activity.When their contents are excessive,they will harm human health and cause environmental pollution.The ratiometric fluorescent probe overcomes the confusion of common biological molecular analysis methods such as electrochemistry,colorimetry,chromatography,etc.Compared with the single fluorescent probe,the ratiometric fluorescent probe is more sensitive and anti-interference.Carbon dots have many advantages including low toxicity,high biocompatibility,and strong light stability,etc.The construction of the ratiometric fluorescent probe based on carbon dots conforms to the new trends in fluorescence probe development.Fluorescent test papers make an important contribution to real-time visual quantitative detection of test objects.This project construct the ratiometric fluorescent probes based on carbon dots for the visual detection of dopamine and ciprofloxacin.Specific studies include the following two points:1.A ratiometric fluorescent probe based on carbon dots and copper nanoclusters was designed to visualize dopamine detection.In this study,carbon dots emitting blue fluorescence were prepared and have an average particle size of approximately 2.7 nm.The maximum excitation wavelength is 340 nm and the maximum emission wavelength is 440 nm.The prepared bovine serum albumin-coated copper nanoclusters with red fluorescence have a regular spherical shape and an average particle size of about 2 nm.The maximum emission wavelength is 640 nm.The probe exhibits a broad concentration range of dopamine from 0.1 to 100 ?M.The detection limit is 32 nm.The test paper can show a clear continuous change from blue to red.This method enables highly sensitive and selective on-site visualization of dopamine in real human serum samples.2.A ratiometric fluorescent probe based on silicon nanoparticles and carbon dots was constructed to visually detect ciprofloxacin.The average particle size of carbon dots is about 2.5 nm,and the maximum emission peak is at 660 nm with a red fluorescence.The carboxylated silicon nanoparticles have an average particle size of about 1.5 nm and a maximum emission wavelength at 426 nm.The method uses a dual-signal fluorescence ratio as a signal output and achieves high sensitivity detection of ciprofloxacin in a wide linear range from 0.1 to 150 ?M.The detection limit is approximately 0.03 ?M.Upon excitation with 365 nm UV light,the solution and test paper can show a clear and continuous color change from red to blue,realizing the on-site visual detection of ciprofloxacin in the real sample.The preparation of the above-mentioned nanoparticle complex ratiometric fluorescent probe satisfies the requirement for green,simple and visual detection of biomolecules.This type of probe has good stability and excellent reproducibility.Combined with portable fluorescent test paper,visible color changes can be observed with the naked eyes.Importantly,this analytical method can be extended to the design of novel ratio fluorescent probes for detecting other analytes by developing new recognition and response groups.