Design,Synthesis And Spectral Properties Of Small Gas Fluorescent Probes

Hydrogen sulfide?H₂S?and sulfur dioxide?SO₂?are common gas signal molecules.The content of these molecules is closely related to the health of the human body.For example,Alzheimer's disease,cardiovascular disease and the like are caused by abnormalities in the content of these molecules.Therefore,detecting these gas signal molecules is of great importance.Because gas small molecules are not easy to capture or quantify,many literatures choose to measure their derivatives or ionic forms.According to the above characteristics,three new fluorescent probes are designed in this paper.The main research contents are as follows: 1.A "turn on" probe 2-1 is based on a disulfide exchange-nucleophilic addition reaction using dicyanisophorone as a fluorophore.This probe can quickly detect H₂S.2-1 and it can be used to detect endogenous and exogenous H₂S in cells.2.On the basis of the probe 2-1,the recognition group is changed to a nitro group,and the ratio type fluorescent probe 3-1 is designed and synthesized.The nitro group is an electron withdrawing group,which hinders the intramolecular charge transfer?ICT?process.After the reaction of 3-1 with H₂S,the electron-withdrawing nitro group is reduced to an electron-donating amino group,and the ICT process is turned on,making the ? conjugate.The system is re-established,emitting red fluorescence.Probe 3-1 enables the detection of H₂S in pure aqueous phase,and 3-1 can be used to detect endogenous and exogenous H₂S in cells.3.H₂S can produce sulfite(SO₃^2-)after the catalysis of enzyme.In order to detect SO₃^2-,probe 4-1 is designed and synthesized.4-1 reacts with SO₃^2-to form a five-membered thiazole ring.The hydrogen bonds between N and H atoms of Imide will block the ?c=n? isomerization,resulting in a change in fluorescence.The probe has good water solubility,high selectivity,low detection limit and low toxicity.At the same time,4-1 can target subcellular organelles and detect SO₃^2- in lysosomes.