“Turn‐on” Fluorescence Chemosensor Based Probing of Cu²⁺ with Excellent Sensitivity: Experimental Study, DFT Calculations and Application in Living Cells and Natural Waters

Abstract

Developing selective, precise, and rapid determination methods for Cu 2 + sensing is of great significance for biological systems, public health, and environmental protection. Hence, a new coumarin-based fluorescent chemosensor 3-((E)-(((E)-3,5di-tert-butyl-2-hydroxybenzylidene)hydrazono) methyl)-7-(diethylamino)-2H-chromen-2-one (HBAC) for Cu 2 + sensing in MeOH:H 2 O (80 : 20, v:v, pH = 7 PBS buffer) media has been constructed. HBAC responded to Cu 2 + with high selectivity and exhibited a relatively low LOD of 7.0 nM and ∼ 22-fold fluorescent enhancement at 461 nm with the addition of Cu 2 + (0.0-5.0 μM). The reaction mechanism of the HBAC-Cu 2 + system has been fully examined by MALDI-TOF-MS, FT-IR, and time dependent-density functional theory (TD-DFT) calculations. The sensing mechanism was occurred due to the chelation enhanced fluorescence (CHEF) and inhibition of PET phenomena. Furthermore, the chemosensor HBAC for Cu 2 + sensing in living systems and natural spring water samples has been successfully utilized, suggesting that the prepared HBAC is an appropriate chemosensor for examining Cu 2 + in biological and environmental systems.

Multifaceted Chiral Probe 2,3-Dihydro-4-hydroxy-chromene Schiff Base in Detecting Cu2+ Ions, l-Histidine, and Indazole: Spectroscopic Investigation and Confocal and Live Cell Imaging

“…Hence, suitable sensors have to be developed for the detection of copper ions (Cu­(I)/Cu­(II)) in organic and environment samples. Generally, the increased level of copper ions causes numerous degenerative diseases like cancer, epilepsy, hepatitis, Parkinson, and Alzheimer. − In this turn, metal ions (copper) can be detected by various techniques such as electrothermal atomic absorption (EAS), flame atomic absorption (FAAS), and inductively coupled plasma mass spectrometry (ICP-AES). − Up to date, several chemosensors for detection of Cu­(II) have been reported. − …”

AIE+ESIPT Active Hydroxybenzothiazole for Intracellular Detection of Cu2+: Anticancer and Anticounterfeiting Applications

“…Copper (Cu 2+ ) is known as the third most abundant trace element in aerobic organisms and it is involved in many biological pathways [26][27][28][29][30]. Various fundamental physiological functions in the body utilize Cu 2+ ions, such as in metalloenzymes, respiration, blood formation, transcriptional events, etc.…”