The Construction And Biosensing Of Hydrazine Fluorescent Probe

Hydrazine is a highly reactive base and a strong reducing agent and used as an important reactant in the field of chemistry,pharmaceuticals and agriculture.However,due to its toxicity,hydrazine is also a threat to the living environment and health of human beings.Therefore,it is of great importance to explore a sensitive and efficient method to detect the trace of hydrazine in the environment and physiological and pathological processes.Fluorescent probes play an important role in environmental science,life science and analytical chemistry because of their high sensitivity,good selectivity,simple operation and many other advantages.In this work,we have designed and synthesized two kinds of fluorescent probes,which have been applied to detect and sense hydrazine in cells.1.We have developed a based benzothiazole fluorescent probe 2-1 for the detection of hydrazine,and the detection limit is 0.087 ?M(2.80 ppb).Upon addition of hydrazine,free phenolic hydroxyl groups appeared through acetyl hydrolysis and hydrazine was generated by the addition reaction of aldehyde and hydrazine.These two processes make the intramolecular charge transfer(ICT).Fluorescent imaging of hydrazine in BT474 cells was successfully demonstrated.2.A novel fluorescein-based �turn-on� probe 3-1 was designed and synthesized,with the double recognition site of phthalimide and acetyl.The probe can identify hydrazine selectively and sensitively,and the detection limit for hydrazine was calculated to be 0.57 ?M(1.83 ppb).After reaction with hydrazine,the selective deprotection phthalimide induced by hydrazine,which destroyed the PET progress between fluorophore and phthalimide.Free phenolic hydroxyl groups appeared through acetyl hydrolysis restored the ICT progress.The opening of spirolactone framework of fluorescein moiety formed the conjugate system between xanthenes moiety and benzene ring.We believed that the releasing of the fluorescein moiety and the opening of lactone ring of fluorescein scaffold worked together leading to the fluorescence enhancement.The probe could also be applied for the imaging of hydrazine in living cells.