A novel benzidine based Schiff base “turn-on” fluorescent chemosensor for selective recognition of Zn2+

A highly selective and sensitive fluorescent chemosensor for Zn2+based on a diarylethene derivative

“…The isomerization of C]N bond was always considered to be the predominant decay process in excited state. 24,43 With the addition of Zn 2+ , the emission intensity dramatically increased associated with a red shi from 464 nm to 513 nm. When the amount of Zn 2+ reached 1 equivalent, the uorescence intensity achieved its maximum with a high quantum yield (F ¼ 0.220) which is 27-fold larger than that of 1o.…”

“…19,20 Up to now, a considerable amount of uorescent sensors targeting transition and heavy metal ions with transient response and splendid selectivity have been reported. [21][22][23][24] As known to all, quinoline as an important ne chemical raw material, mainly used for the synthesis of pharmaceutical, dyes and a variety of chemical catalysts. [25][26][27][28][29] On the other hand, an increasing number of photochromic molecular systems have been used as uorescent probes to detect metal ions in recent years.…”

Photostable Voltage-Sensitive Dyes Based on Simple, Solvatofluorochromic, Asymmetric Thiazolothiazoles

“…Small-molecule fluorophores are attractive molecular tools for environmental sensing applications and biosensing/bioimaging techniques because of their high microenvironmental sensitivity, selectivity, and temporal resolution . Fluorescent molecules can either turn on/off their fluorescence or chromically shift their emission through the binding or interaction of various metal ions, − reactive oxygen species, organic toxins, or cell organelles/membranes , and can greatly enhance cell fluorescence microscopic imaging . Molecular sensors with large fluorescence Stokes shifts are advantageous for these applications due to a low overlap between excitation and emission …”

Recent progress in chemosensors based on pyrazole derivatives

“…65 In the past decade, uorescent chemosensors for Zn 2+ ions have attracted great attention because of the biological signicance of zinc combined with the simplicity and high sensitivity of uorescence assays. [66][67][68] Transitions ions with closed-shell d-orbitals, such as Zn 2+ , do not introduce low-energy metal-centered or charge-separated excited states into the molecule, so energy and electron transfer processes cannot take place. Thus, when Zn 2+ is added, the uorescence intensity of their complexes tends to increase, 69 so the interaction of Zn 2+ ions with pyrazolines follows a "turn-on" behavior in terms of the uorescence properties.…”