Synthesis And Cell Imaging Studies Of Fluorescent Probes For Sensing Al³⁺ And PH

Chapter 1: The mechanism of fluorescence generation and the recognition mechanism of fluorescent probes are briefly described,and the fluorescent probes for detecting Al³⁺ and p H are reviewed.Chapter 2: A novel Schiff-base fluorescent probe N-?2,5-dihydroxybenzoyl?pyridine-2-formylhydrazine?L?,for sensing Al³⁺ was synthesized by a simple one-step reaction.After the probe L was combined with Al³⁺,the solution color changed from colorless to yellow,and the fluorescence intensity at 533 nm was significantly enhanced,enabling the selective recognition and detection of Al³⁺ with a detection limit of 7.27×10-7 M.The binding pattern was further determined by 1H NMR and ESI-MS.In addition,probe L was successfully applied for intracellular Al³⁺ imaging analysis.Chapter 3: A new Schiff-base fluorescent probe RM was designed and synthesized using a rhodamine B as the fluorophore group,and a morpholine ring as the lysosome-targeting group.When the probe was combined with Al³⁺,the fluorescence intensity at 578 nm significantly increased and exhibited a good linear relation with Al³⁺ concentration within the range of 40-100 ?M.In addition,the co-location fluorescence imaging experiments confirmed the co-staining fluorescence imaging of probe RM with a commercial green lysosome-selective dye.Moreover,this is the first fluorescent probe to achieve specific detection of Al³⁺ in lysosomes.Chapter 4: The p H fluorescent probe BPN was designed and synthesized based on the mechanism of PET by using a 1,8-naphthalene diformylimide derivative as the fluorophore group and a piperazine ring as the p H responding site.The fluorescence intensity of the probe at 526 nm showed significant p H-dependent enhancement,with a large Stokes shift of 136 nm.Meanwhile,the probe shows high selectivity,good water solubility and low toxicity.The p Ka?6.69?and p H response linear range?6.4-8.0?of the probe are very suitable for cytoplasmic matrix p H imaging.Imaging of He La cells revealed that the real-time in situ visualization fluorescence imaging of p H fluctuations in cytoplasmic matrix stimulated by drugs was successfully achieved by the probe.