Rhodamine B-based Molecular Fluorescence Probe Imaging Detects Pd²⁺ And Zn²⁺ In Cells And In Vivo

Among the detection methods,the advantages of small molecule fluorescent probes are outstanding,for example,it can achieve rapid detection targets,high sensitivity,switch operation,and response ions under neutral conditions.Therefore,small molecule fluorescent probes has received extensive attention and development from scientists in recent years.Palladium is a heavy metal that is extremely common in life and plays an important role.Its advantages are its stable nature,good biocompatibility and variable chemical properties,so it is used in alloy materials,various jewelry,medical crowns,chemical fuel cells,reaction catalysts,and catalytic converters for automobiles.However,it is worth mentioning that the widespread use of palladium also poses a certain hazard to the health of humans and other organisms,mainly because palladium cannot be biodegraded.Therefore,the palladium of various products may accumulate in the food chain.When the amount of palladium accumulates to a certain extent,it may cause threats to human's health.Therefore,it is imperative to develop a method that is highly efficient and has good selectivity and low detection limit for palladium.In recent years,another heavy metal,Zn²⁺,has attracted great interest of chemists because of its special chemical properties,as well as in gene transcription,immune function and mammalian reproduction,brain function and pathology,metalloproteinase regulation,nerve signal translation and cell apoptosis,and certain pathological processes such as Alzheimer's disease,epilepsy.Epilepsy,ischemic stroke,infantile diarrhea and other basic biological processes play an important role.However,elevated levels of zinc in humans are associated with neurodegenerative diseases and other diseases.These problems indicate that there is an urgent need to develop effective methods to detect zinc ions.In order to solve these problems,we designed and synthesized two fluorescent small molecule probes based on rhodamine structure for detecting Pd²⁺and Zn²⁺to realize fluorescence detection of cells and living bodies.This paper mainly includes the following contents:1.Based on the good optical properties of Rhodamine,we designed and synthesized a fluorescent probe for detecting Pd²⁺.The probe utilizes the open-loop of the rhodamine B internal hydrazide structure to cause a strong change in fluorescence,and is an ideal design of the Off-On molecule fluorescent probe model.When Pd²⁺is encountered,the rhodamine B internal hydrazide structure is induced to open the ring,the PET effect is inhibited,and the fluorescent radiation is enhanced to reflect the enhanced fluorescent signal.Firstly,the structure of the probe was determined by mass spectrometry and nuclear magnetic means.Then the spectral properties of the probe were detected by fluorescence and ultraviolet absorption spectroscopy,and the experimental conditions were optimized to realize the in vitro detection of Pd²⁺.The probe was then applied to cells and in vivo to verify that the probe can be used to detect Pd²⁺in cells and in vivo,and that Pd²⁺was found to be the most concentrated in the spleen of mice.2.Based on the good optical properties of rhodamine,we designed and synthesized a fluorescent probe for detecting Zn²⁺.The probe utilizes the open-loop of Rhodamine B to cause strong changes in fluorescence,and is an ideal design of the Off-On small molecule fluorescent probe model.When Zn²⁺is encountered,the rhodamine B internal hydrazide structure is induced to open the ring,the PET effect is inhibited,and the fluorescent radiation is enhanced to reflect the enhanced fluorescent signal.Firstly,the structure of the probe was determined by mass spectrometry and nuclear magnetic means,which was used as a basis for the subsequent in vitro verification of the detection of Zn²⁺by probes and the detection of Zn²⁺in cells and in vivo.