Simple Fluorescence Turn-On Chemosensor for Selective Detection of Ba²⁺ Ion and Its Live Cell Imaging

Abstract

A phenoxazine-based fluorescence chemosensor 4PB [(4-(tert-butyl)-N-(4-((4-((5-oxo-5H-benzo­[a]­phenoxazin-6-yl)­amino)­phenyl)­sulfonyl)­phenyl)­benzamide)] was designed and synthesized by a simple synthetic methods. The 4PB fluorescence chemosensor selectively detects Ba2+ in the existence of other alkaline metal ions. In addition, 4PB showed high selectivity and sensitivity for Ba2+ detection. The detection limit of 4PB was 0.282 μM and the binding constant was 1.0 × 106 M–1 in CH3CN/H2O (97.5:2.5 v/v, HEPES = 1.25 mM, pH 7.3) medium. This chemosensor functioned through the intramolecular charge transfer (ICT) mechanism, which was further confirmed by DFT studies. Live cell imaging in MCF-7 cells confirmed the cell permeability of 4PB and its capability for specific detection of Ba2+ in living cells.

Review on Nanoparticles and Nanostructured Materials: Bioimaging, Biosensing, Drug Delivery, Tissue Engineering, Antimicrobial, and Agro-Food Applications

“…Rare-earth metals are primarily used to develop nanoparticles with persistent luminescence [ 58 ]. However, the major issue linked to the use of rare-earth metal-based nanoparticles in vivo is their potential cytotoxicity and their low tunability for surface modification [ 59 , 60 ]. Therefore, non-toxic conjugated polymer nanoparticles with tremendous optical properties have been developed to act as persistent luminescence materials that can replace the conventional rare-earth metal-based nanoparticles.…”

Intelligent demethylase-driven DNAzyme sensor for highly reliable metal-ion imaging in living cells

“…13,14 To explore the vital role of metal ions in biological processes, probes that enable the accurate imaging of metal ions in living cells are of great promise. Numerous fluorescent probes have thus been developed for intracellular imaging metal ions, and these include small organic molecules [15][16][17] and fluorescent proteins. [18][19][20][21][22] However, these small molecule probes are only suitable to a limit range of metal-ion targets and might bring undesired biotoxicity to live cells.…”

Simple fluorescence optosensing probe for spermine based on ciprofloxacin-Tb3+ complexation

“…Conventional methods for the quantitative determination of spermine, such as chromatographic techniques [21][22][23], immunoassays [24,25], electrophoresis [26][27][28], and electrochemical [29,30] have been developed, but the time consuming, skilled personnel, and high cost of related equipment significantly affect the popularity of these methods. In contrast, fluorescence methods have become a popular method due to the versatility, sensitivity, low detection, and visual capacities [31][32][33]. For example, Fletcher and Bruck [34] reported an SP sensor based on "turn-on" fluorescence of dicarboxylated ethynylarene by mixing Pb(II) cations with SP.…”