1. Aza-Crown-Based Macrocyclic Probe Design for "PET-off" Multi-Cu 2+ Responsive and "CHEF-on" Multi-Zn 2+ Sensor: Application in Biological Cell Imaging and Theoretical Studies.
- Author
-
Ghorai P, Ghosh Chowdhury S, Pal K, Mandal J, Karmakar P, Franconetti A, Frontera A, Blasco S, García-España E, Parui PP, and Saha A
- Subjects
- Humans, Aza Compounds chemistry, Optical Imaging, Molecular Structure, HeLa Cells, Crown Compounds chemistry, Crown Ethers chemistry, Spectrometry, Fluorescence, Zinc chemistry, Zinc analysis, Copper chemistry, Copper analysis, Fluorescent Dyes chemistry, Fluorescent Dyes chemical synthesis, Macrocyclic Compounds chemistry, Macrocyclic Compounds chemical synthesis, Density Functional Theory
- Abstract
The work represents a rare example of an aza-crown-based macrocyclic chemosensor, H
2 DTC (H2 DTC = 1,16-dihydroxy-tetraaza-30-crown-8) for the selective detection of both Zn2+ and Cu2+ in HEPES buffer medium (pH 7.4). H2 DTC exhibits a fluorescence response for both Zn2+ and Cu2+ ions. The reversibility of the chemosensor in its binding with Zn2+ and Cu2+ ions is also examined using a Na2 EDTA solution. H2 DTC exhibits a chelation-enhanced fluorescence (CHEF) effect in the presence of Zn2+ ions and a quenching effect (CHEQ) in the presence of paramagnetic Cu2+ ions. Furthermore, the geometry and spectral properties of H2 DTC and the chemosensor bound to Zn2+ have been studied by DFT and TDDFT calculations. The limit of detection (LOD) values are 0.11 × 10-9 and 0.27 × 10-9 M for Cu2+ and Zn2+ , respectively. The formation constants for the Zn2+ and Cu2+ complexes have been measured by pH-potentiometry in 0.15 M NaCl in 70:30 (v:v) water:ethanol at 298.1 K. UV-vis absorption and fluorometric spectral data and pH-potentiometric titrations indicate 1:1 and 2:1 metal:chemosensor species. In the solid state H2 DTC is able to accommodate up to four metal ions, as proved by the crystal structures of the complexes [Zn4 ( DTC )(OH)2 (NO3 )4 ] ( 1 ) and {[Cu4 ( DTC) (OCH3 )2 (NO3 )4 ]·H2 O}n ( 2 ). H2 DTC can be used as a potential chemosensor for monitoring Zn2+ and Cu2+ ions in biological and environmental media with outstanding accuracy and precision. The propensity of H2 DTC to detect intracellular Cu2+ and Zn2+ ions in the triple negative human breast cancer cell line MDA-MB-468 and in HeLa cells has been determined by fluorescence cell imaging.- Published
- 2022
- Full Text
- View/download PDF