Synthesis And Application Research Of Hemicyanine-based Near-Infrared Ratiometric Fluorescent Probes

Over the past decades,near-infrared ratiometric fluorescent probes have shown great potential for applications in monitoring a variety of important biological species in vivo and in vitro,as they have abilities of quantitative analysis,good cell permeability,high sensitivity and low toxicity.The hemicyanine compounds can be used to design and synthesize near-infrared fluorescent probes because of their good optical properties and stability.Consequently,in this thesis,two hemicyanine-based fluorescent probes 1 and 2 were designed and synthesized,and their recognition properties were studied.The main contents are as follows:1.A near-infrared ratiometric fluorescent probe 1 was synthesized with 4-hydrazinobenzoic acid hydrochloride and 3-aminophenol.Probe 1 has good photostability and thermostability.When the excitation wavelength is 470 nm,we can get the ratio of fluorescent intensity I570/I720,while when the excitation wavelength is 630 nm,we can get the fluorescent intensity I720.Probe 1 can detect hydrazine hydrate and arginine sensitively and selectively with any one of the two excitation wavelengths,and shows a good anti-interference capability.The detection limits toward arginine and hydrazine hydrate are 138 nM and 339 nM,respectively.Furthermore,upon the addition of arginine or hydrazine hydrate,the solution of probe 1 displays fluorescence and color change,indicating that probe 1 can be a fluorescent and colorimetric dual channel probe for arginine and hydrazine hydrate.Cell imaging experiments have shown that probe 1 can act as the Lysosome-Tracker,and can detect hydrazine hydrate and arginine in live cells.2.A near-infrared ratiometric fluorescent probe 2 was designed with 1,1,2-trimethyl-1H-benzo[e]indole and 3-aminophenol.Probe 2 has good photostability and thermostability.When the excitation wavelength is 420 nm,we can get the ratio of fluorescent intensity I520/I700,while when the excitation wavelength is 620 nm,we can get the fluorescent intensity I700.Probe 2 can detect hydrazine hydrate and arginine sensitively and selectively with any one of these two excitation wavelengths,and also has good anti-interference.Comparing with probe 1,the detection limits of probe 2 are lower,the detection limits toward arginine and hydrazine hydrate are 11.7 nM and 242 nM,respectively.Furthermore,probe 2 can detect arginine and hydrazine hydrate colorimetrically.Therefore,probe 2 can also be used as a dual channel colorimetric near-infrared fluorescent probe for the detection of arginine and hydrazine hydrate.