A highly fluorescent chemosensor for Zn²⁺and the recognition research on distinguishing Zn²⁺from Cd²⁺

Abstract

A new fluorescent sensor, 2-(2-oxo-2-(quinolin-8-ylamino)ethoxy)-N-(pyridine-2-ylmethyl) benzamide (L), composed of a quinoline group as the fluorogenic unit and a pyridin-2-ylmethanamine as the binding unit for metal ions has been synthesized. The sensor shows excellent selectivity and sensitivity with a fluorescence enhancement to Zn(2+) over other cations in acetonitrile aqueous solution. The X-ray crystal structure analysis reveals that sensor L coordinates to Zn(2+)via a 1 : 1 binding mode but to Cd(2+)via a 2 : 1 binding mode, which lead to a different spatial arrangement of the fluorogenic unit in these complexes. In addition, density functional theory calculations on L, and the Zn(2+)/L and Cd(2+)/L complexes also imply that the different structures of L significantly affect the molecular orbital energy levels and electron transition, which would result in the spectral changes to distinguish Zn(2+) from Cd(2+). The absorption study results may also suggest the Cd(2+) in the complex can be displaced by Zn(2+). Furthermore, the fluorescence imaging of Zn(2+) in living cells was obtained.

A Phenyl Thioether‐Based Probe: Zn2+ Ion Sensor, Structure Determination and Live Cell Imaging†

“…Herein we report, a diformyl thioether based fluorescent chemosensor, H 2 ‐SAP , prepared by simple Schiff base condensation procedure ( Scheme S1 ) which displays selective fluorescence sensitivity towards Zn 2+ by chelation enhancement fluorescence effect (CHEF) process in presence of large number of ions and could identify Zn 2+ in nM level, much lower than so far reported results . The composition of the complex formed between Zn 2+ and H 2 ‐SAP has been supported by spectroscopic data (Mass, Job's plot) and single crystal X‐ray crystallography.…”

“…Chemical sensing via fluorescence signal recognition has been first established during 1980s . Since then researchers are engaged to design various types of fluorogenic sensors to detect Zn 2+ in different environment including intracellular measurements, Fluorogenic motifs like naphthyl, Diformyl derivative, terpyridyl, quinoline,, imidazoylpyridyl,, bipyridyl,, pyrenyl derivatives, terphenyl‐based motif, pyrimidinyl attached Schiff‐base, pyrazolyl,, BINOL, rhodamine,, catechol appended Schiff base, coumarinyl Schiff base, thiazolyl derivative etc. have successfully been used.…”

Zn2+ Recognition for Pathogenesis of Pick's Disease via a Luminescent Test Kit

“…Indeed the cells were sparkling with blue emission which signifies the in vitro detection of Zn 2+ (Figure 8). The cells incubated in L1 only and in urine sample were used as control which has almost negligible emission in comparison to the observed fluorescence in Figure 8 [52–54] …”

“…The cells incubated in L1 only and in urine sample were used as control which has almost negligible emission in comparison to the observed fluorescence in Figure 8. [52][53][54]…”

An efficient vanillinyl Schiff base as a turn on fluorescent probe for zinc(ii) and cell imaging

“…Different methods for the detection of zinc ions have been proposed, such as atomic absorption spectrometry, 8 inductively coupled plasma mass spectroscopy (ICPMS), 9 inductively coupled plasma-atomic emission spectrometry (ICPAES), 10 and voltammetry. [15][16][17][18][19][20][21][22][23][24] In particular imine based sensors have drawn special attention. 14 Because of 3d 10 electronic configuration, Zn 2+ is spectroscopically silent and numerous fluorescent sensors have been characterized to determine its concentration in living cells over the last decade.…”