摘要
本文利用光致诱导电子转移(PET)类探针的设计策略,合成了一种以吡喃腈类衍生物为母体、哌嗪为探测基团的新型pH荧光探针DCM-PA。结果表明:DCM-PA的最大吸收波长(λ_(abs))和最大荧光发射波长(λ_(em))分别为421nm和590nm,斯托克斯位移近170nm。在pH=2~12范围内,DCM-PA的荧光强度随pH的升高而降低,pH=2时的荧光强度是pH=12时荧光强度的12倍;DCM=PA的pKa值为7.2,在pH=6~9范围,荧光强度与pH呈良好的线性关系。对比试验证实DCM-PA实现了pH检测的机理:酸性条件下,哌嗪基团与质子结合削弱了其供电子能力,使DCM-PA荧光增强;碱性条件下,哌嗪通过PET作用使探针荧光猝灭。抗干扰试验表明,DCM-PA在中性酸碱度下对多种阴、阳离子均具有良好的抗干扰能力。
A novel pH fluorescent probe(DCM-PA)was synthesized by employing dicyanomethylene-4H-pyran derivative as the fluorophore and piperazine as the response unit.The maximum absorption wavelength(λabs)and maximum emission wavelength(λem)were tested to be 421 nm and 590 nm,respectively.This means that the stokes shift is near to 170 nm.It was found that the fluorescence intensity gradually increased with the increase of pH value in the pH range of 2-12.The p K a of DCM-PA was determined to be 7.2.In the range of pH=6-9,there exists a good linear relationship between the fluorescence intensity and pH value.The response mechanism of the pH probe was revealed by the control experiment:Under acidic conditions,the electron donating ability of piperazine group will weaken after combining with proton,leading to the enhancement of the fluorescence intensity.Under alkaline conditions,the fluorescence will be quenched by the photoinduced electron transfer(PET)process.Moreover,it was found that DCM-PA exhibited a good anti-interference ability to different cations and anions.
作者
常顺周
相开强
明伟
张志忠
田宝柱
张金龙
CHANG Shunzhou;XIANG Kaiqiang;MING Wei;ZHANG Zhizhong;TIAN Baozhu;ZHANG Jinlong(Research Institute of Physical and Chemical Engineering of Nuclear Industry,Tianjin 300180,P.R.China;Key Laboratory for Advanced Materials,School of Chemistry&Molecular Engineering,East China University of Science and Technology,Shanghai 200237,P.R.China)
出处
《影像科学与光化学》
CAS
CSCD
2018年第5期425-433,共9页
Imaging Science and Photochemistry
基金
国家自然科学基金项目(21573069)
国防科工业局军品配套项目(JPPT-125-4-076)
关键词
荧光探针
pH
吡喃腈
光致诱导电子转移
fluorescent probe
pH
dicyanomethylene-4H-pyran
photoinduced electron transfer
