Near-infrared Fluorescent Probes For Detecting Bioactive Molecules

In recent years,various methods for detecting signal factors in organisms have been continuously developed.Fluorescent probes have stood out from the crowd of detection methods due to their simple operation,good anti-interference,high sensitivity,high selectivity and low detection limit.It has attracted attention in the field of biochemis TYR and has gradually become an important analytical tool in the field of biochemical sensing.And the concentration of signal factors in living organisms is closely related to some diseases.Therefore,designing near-infrared fluorescent probes that can shield most biological background fluorescence with little damage to living systems is used to selectively detect signal factors.It shows great practical value.The near-infrared fluorescent probe designed and constructed in this paper is aimed at two biological signal factors,and its application and imaging in and outside the cell have been studied.Firstly,we designed and synthesized the fluorescent probe for detecting tyrosinase(TYR).This probe(CHMC-Dopa)is synthesized by amination of chloro-hydroxy cyanine fluorophores and dopamine hydrochloride.The identification group is o-phenyl dihydroxy group,which has been characterized by high-resolution mass spectrome TYR and nuclear magnetic resonance spectroscopy.Before reacting with TYR,the emission wavelength of the fluorescent probe is 628 nm,which is close to the near-infrared region,and is favorable for in vivo imaging,after reacting with TYR,the probe showed 10-fold fluorescence decrease,the and CHMC-Dopa shows a high reaction rate,good biocompatibility and sensitivity.Then,we designed the second fluorescence probe for detecting TYR.The structure of second probe is dicyanomethylene-4H-pyran as a fluorophore and m-hydroxyphenyl as a recognition group.Compared with hydroxyl groups,m-hydroxy groups are harder to react with active oxygen in other organisms,so there are better selectivity.DCM-OH has perfect emission wavelength in the near-infrared region and is also a good choice for fluorophores.The synthesized fluorescent probe DCM-Ph-OH-OH has been characterized by high resolution mass spectrome TYR,but in the test with TYR,the probe did not show obvious reaction phenomenon.Finally,we synthesized a semi-cyanine dye-based fluorescent probe(Cy-SH)to detect signal molecules HNO in vivo.The recognition group of this fluorescent probe is the thiol group,and the thiol group reacts to HNO,the electron transfers,the ester group is cut off,and fluorescence appears.Cy-OH has good biocompatibility and good near-infrared emission wavelength.However,in the test with HNO,the probe did not show a reaction with HNO.