A novel chromo- and fluorogenic dual sensor for Mg²⁺and Zn²⁺with cell imaging possibilities and DFT studies

Abstract

A diformyl-p-cresol (DFC)-8-aminoquinoline based dual signaling probe was found to exhibit colorimetric and fluorogenic properties on selective binding towards Mg(2+) and Zn(2+). Turn-on fluorescent enhancements (FE) as high as 40 fold and 53 fold in 9 : 1 MeCN/water (v/v) at pH 7.2 in HEPES buffer for Mg(2+) and Zn(2+), respectively, were observed. The binding constants determined from the fluorescence titration data are: K = (1.52 ± 0.21) × 10(5) M(-1) and (9.34 ± 4.0) × 10(3) M(-2) at n = 1 and 0.5, for Mg(2+) and Zn(2+), respectively. The L : M binding ratios were also determined by Job's method, which support the above findings. This is further substantiated by HRMS analysis. Due to solubility in mixed organo-aqueous solvents as well as cell permeability it could be used for the in vitro/in vivo cell imaging of Mg(2+) and Zn(2+) ions with no or negligible cytotoxicity. This probe could be made selective towards Mg(2+) over Zn(2+) in the presence of TPEN, both under intra- and extracellular conditions and is superior to other Mg(2+) probes which suffer from selectivity of Mg(2+) over Ca(2+) or Zn(2+). Furthermore the dissociation constant (Kd = 6.60 μM) of the Mg(2+)-() complex is far lower than the so far reported Mg(2+) probes which fall in the mM range.

A turn-on fluorescent chemosensor based on acylhydrazone for sensing of Mg2+ with a low detection limit

“…Nonetheless, reports about uorescent sensors for Mg 2+ are still few compared with those on other important ions, such as Zn 2+ , Al 3+ , Hg 2+ and CN À . [14][15][16][17][18][19][20][21][22][23][24][25][26][27] Even so, some methodologies for detecting Mg 2+ are oen interfered with by Zn 2+ and Ca 2+ . To date, as far as we know, b-diketone, crown ether derivatives, and nanoparticles have been employed for selective detection of Mg 2+ ions.…”

Di-oxime based selective fluorescent probe for arsenate and arsenite ions in a purely aqueous medium with living cell imaging applications and H-bonding induced microstructure formation

“…The ligand was prepared by a literature method 33,34 and characterized by various spectroscopic techniques (Fig. S1 † The photophysical properties of DFC-DO were studied in a purely aqueous medium at pH 7.24, μ = 0.05 M, NaCl, buffered with 10 mM HEPES.…”

A novel and simple solvent-dependent fluorescent probe based on a click generated 8-aminoquinoline–steroid conjugate for multi-detection of Cu(ii), oxalate and pyrophosphate

“…42 And 8-aminoquinoline and its derivatives are well-known excellent building blocks for constructing highly selective uorescent sensors of transition metal cations. 36,[43][44][45][46] Meanwhile, the bridging 1,2,3-triazole group was introduced via click chemistry in order to offer not only a straightforward strategy for the linkage of various functionalities, but also a potential binding site for both metal ions and anions, 47,48 which is very benecial for multi-target analysis.…”