A novel ‘‘donor-π-acceptor’’ type fluorescence probe for sensing pH: mechanism and application in vivo

A “weak acid and weak base” type fluorescent probe for sensing pH: mechanism and application in living cells

“…Intracellular pH (pHi) plays a vital role in cellular events, such as ion transport, muscle contraction, multidrug resistance, calcium regulation, cell growth, and apoptosis. [1][2][3][4] Abnormal pHi values cause many common diseases, including neurodegenerative disorders, cystic brosis, Alzheimer's disease, and cancer. [5][6][7] In distinct prokaryotic species and diverse subcellular compartments of eukaryotic cells, pHi values can range from highly acidic to basic.…”

An acidic pH fluorescent probe based on Tröger's base

“…Before the addition of acid, DMSO solution of TBPP exhibited an intense emission band around 490 nm with a large Stokes shi of 149 nm. 29,30,34,35 The large Stokes shi should help to reduce the excitation interference. Upon increasing the amount of H + , the uorescence intensity reduced gradually until quenched completely.…”

“…27,28 In addition, N-heterocyclic derivatives are ideal substances for use as hydronium ion indicators owing to the high sensitivity and the exceptionally rapid rates of proto transfer occurring in acidbase equilibrium process. 11,29,30 With this in mind, we designed and synthesized a new compound TBPP based on TB by introducing the pyridine electron-withdrawing group into TB framework. We expect that optical change could be achieved through the transformation between the neutral TBPP and non-uorescence ionic pyridinium salt by protonation.…”

Two Pyridine‐Based Fluorescent Probes for Sensing pH

“…As one kind of important probes, pyridine derivatives are used widely as a lot of sensors including pH probes. [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] The nitrogen atom within the pyridine ring has been widely used because of the combinable nature between the lone pair electron of nitrogen and proton. In addition, some groups reported a lot of compounds that bridged pyridine and aryl groups through acrylonitrile and respectively studied their properties such as kinetics, spectroscopy, pH sensing, lightemitting diodes, etc.…”

“…As one kind of important probes, pyridine derivatives are used widely as a lot of sensors including pH probes [28–45] . The nitrogen atom within the pyridine ring has been widely used because of the combinable nature between the lone pair electron of nitrogen and proton.…”