Synthesis And Application Of Novel Naphthalimide And Rhodamine Fluorescent Probes

Due to many advantages such as good selectivity,high sensitivity convenient and so on,fluorescent probes draw much attention by scholars.However,the application of fluorescent probes are subject to some limitations such as complex molecular structure,poor water solubility,lack of specificity and poor membrane permeability.Therefore,the design and systhesis of fluorescent probes and looking for fluorescent probes with simple molecular structure,water solubility,high sensitivity,good selectivity and well membrane permeability have the vital significance in the field of chemsity.Naphthalimide and rhodamine draw more attention in the field of chemsity because of their strongly fluorescence,good photostability and introduction of various substituents or receptor unit to molecules easily.Based on the features of naphthalimide and rhodamine,this paper has systhesized four fluorescent.probes(Probe 1、Probe 2、Probe 3 and Probe 4)and studied fluorescence properties through a variety of analytical methods.1.Rhodamine B-based schiff base fluorescent Probe 1 was synthesized by rhodamine B and 4-(N,N-diethylamino)-2-hydroxy-benzaldehyde.The results show that Probe 1 can be used for "off-on" probe in detection of Cu2+and L-Met with high sensitivity and selectivity.Cu2+ can quench the fluorescence of Probe 1 through coordination interaction,while L-Met can show stronger binding ability to Cu2+and recover the fluorescence of Probe 1.The probe further could be applied to detect Cu2+and L-Met in Hela cells via intracellular fluorescent imaging.2.Naphthalimide-based schiff base fluorescent Probe 2 was synthesized by 4-bromo-1,8-naphthalimide and 2,4-dihydroxy-benzaldehyde.The results show that Probe 2 can be used for the detection of Fe3+ with high sensitivity and selectivity and the color change of solution can be observed by the naked eye.With the addition of Fe3+,the fluorescence intensity of Probe 2 weakened gradually.When the concentration of Fe3+ reached 50 uM,the quenching degree was 65%.The probe further could be applied to detect Fe3+ in Hela cells via intracellular fluorescent imaging.3.Naphthalimide-based schiff base fluorescent Probe 3 was synthesized by 4-bromo-1,8-naphthalimide and 2,4-dihydroxy-benzaldehyde.Probe 3 can be used for the determination of pH between 8 and 12.Most metal ions and anions do not interfere with the determination of pH.The quantum yield of the Probe 3 was 65.5%,and the fluorescence was almost unchanged in one month.Finally,this probe could be applied to the imaging in living hela cells successfully.4.Naphthalimide-based schiff base fluorescent Probe 4 was synthesized by 4-bromo-1,8-naphthalimide and 2-formylphenyl acrylate.The results show that Probe 4 can be used for "off-on" probe in detection of cysteine and Cu2+with high sensitivity and selectivity.Cysteine can quench the fluorescence of probe 4 through chemical reaction,while Cu2+can quench the fluorescence of Probe 4 through coordination interaction,.The probe further could be applied to detect cysteine and Cu2+ in Hela cells via intracellular fluorescent imaging.