ABSTRACT
It is very necessary to develop real-time, highly sensitive and selective fluorescent probes for hypochlorite (ClO-) in living cells owing to hypochlorite's important role in pathological and physiological processes and its short life. Herein, a pyrene Schiff's base derivative was successfully developed for real-time (within seconds), highly sensitive detecting ClO- with a low detection limit (5.7â¯nM) and wide pH range (4.0-11.0) based on nucleophilic addition and subsequent hydrolysis mechanism. The probe has aggregation-induced emission properties and emits yellow fluorescence (544â¯nm) in PBS solution, while it exhibits blue fluorescence in other organic solvents (426â¯nm (THF) - 460â¯nm (MeOH)). The probe can be used to response ClO- in A549â¯cells with low cytotoxicity, a good cell membranes penetration and good biocompatibility. Cell uptake experiment indicates that probe getting into the cells is energy-dependent and is not attributed to endocytosis. Moreover, the probe is successfully used in real water sample to detect ClO- and it can be expected to be applied to ClO- participated biological and pathological functions in biological systems.
Subject(s)
Fluorescent Dyes/chemistry , Hypochlorous Acid/analysis , Pyrenes/chemistry , Schiff Bases/chemistry , A549 Cells , HeLa Cells , Humans , Limit of Detection , Optical Imaging/methodsABSTRACT
Aluminum is known as the most ubiquitous metal in earth's crust but its excessive exposure will cause damage to environment and health of the organism. Here, a turn-on Schiff base fluorescence probe STH based on excited state intramolecular proton transfer and photoelectron transfer processes for Al3+ detection with fast response rate (within minutes), low detection limit (4.26×10-8M), high selectivity and reasonable pH application range (5.0-8.0) was developed. Fluorescence titration experiments show that probe STH has an excellent linear relationship (R2=0.9694) with Al3+ concentration and could be applied to quantitatively recognize Al3+ in real-water samples. Based on Job's plot and in situ mass spectra, two STH molecules will complex with Al3+ to form 2:1 complexation with oxygen atoms of hydroxyl and carbonyl groups and nitrogen atom of CN bond participating in coordination.