Construction And Application Of Near-infrared Fluorescent Probes

Fluorescent probe is an important research field of biochemical sensing.It has been attracted great interest for its high stability,low detection limit,good chemical selectivity and convenient operation in analysis.Furthermore,based on the development of optical analysis,fluorescence imaging has become an important tool for researchers,especially in the area of analysis and biology.Near-infrared fluorescent probe can dramatically reduce the cellular auto-fluorescence interference and photo-damage to tissues or organelles,and improve the accuracy of optical analysis.Thus,developing near-infrared fluorescent probe will have a great importance.Based on these problems,herein,we report two NIR fluorescent probes for specific recognition of HNO and LAP in vitro and in vivo.(1)We constructed a metal-free NIR fluorescent probe(DCM-P),which was realized the highly chemoselective detection of HNO in vitro and in vivo.DCM-P contains a NIR fluorophore,dicyanomethylene-4H-pyran(DCM),as the reporter and a triarylphosphine as the recognition moiety.After analysis by nuclear magnetic resonance spectroscopy and high resolution mass spectrometry,the obtained data is consistent with its structure.Upon exposure to HNO,the probe emits fluorescence at the wavelength of 688 nm.Moreover,DCM-P shows higher chemoselective detection and faster response to HNO in the presence of various biological relevant reductants,and is successfully employed to trap nitroxyl in different living cells and zebrafish models.These results suggest that DCM-P is a suitable near-infrared metal-free fluorescent probe for motoring nitroxyl in living samples.(2)We constructed a NIR fluorescent Probe,CHMC-M-Leu,for specific recognition of Leucine aminopeptidase(LAP).In this project,we report a water-soluble near-infrared(NIR)fluorescent probe(CHMC-M-Leu)for specificmonitoring LAP in vitro and in vivo.The novel fluorescent probe(CHMC-M-Leu)contains a NIR-emitting fluorophore(CHMC-M)as the reporter and L-leucine residue as the enzyme-active trigger moiety which are linked together by a p-aminobenzyl alcohol(PABA)section.After analysis by nuclear magnetic resonance spectroscopy and high resolution mass spectrometry,the obtained data is consistent with its structure.Upon exposure to LAP,the fluorescence at 625 nm gets an impressively enhancement,which belongs to near-infrared region and its benefit for imaging in vivo.Furthermore,the novel fluorescent probe exhibits fast response and highly chemoselective detection of LAP in various bio-related species.In addition,CHMC-M-Leu shows favourable cellular uptake and was successfully used to monitoring endogenous LAP in living cells.