Highly Reversible'Off-On-Off'Dual-channel Fluorescence Probe Based on Amino Pyrazole and Phenothiazine for Sensing Extremely Alkaline Solution

摘要

Acid-base balance is related to many cell functions,and its disorders can lead to many diseases.Real-time detection of intracellular pH fluctuation is very important to prevent many diseases and environmental water samples.Here,we report a dual-channel fluorescence probe PTZ-aminopyrazole based on low-cost phenothiazine and 3-aminopyrazole,which can detect pH fluctuation highly sensitively through protonation under acidic condition and deprotonation under alkaline condition.The probe exhibits a fluorescence intensity and UV absorbance characteristics in the extreme acidity range of 2.6-5.5 and especially in the extreme alkaline range of 11.1-13.8,respectively.In addition,PTZ-aminopyrazole has high pH-selective reaction to metal ions,good reversibility and excellent photostability.Furthermore,PTZ-aminopyrazole can be fixed on a test paper,which shows a rapid and reversible colorimetric response to HCl/NaOH vapor with naked-eye.