17 research outputs found
Thiazolidine-Based Fluorescent Chiral Ionic Liquids for Trace Copper(II) Ion Sensing
This study presents a comprehensive analysis of the synthesis and photophysical properties of thiazolidine-functionalized chiral ionic liquids (CILs) derived from L-cysteine. The synthesis involves a four-step route, encompassing N-protection, coupling reactions with bromoalcohols, and ionic liquid formation. The optical properties of the compounds were evaluated using UVâVis absorption and fluorescence emission spectroscopies, revealing distinct behavior for different heterocycles and counter-ions. Notably, the investigation reveals that thiazolidine-based CILs exhibit unconventional intrinsic luminescence characteristics. Building upon these photophysical properties, an interaction study was conducted between copper (II) and the CILs. The findings exhibit a robust linear relationship between the optical response and the concentration of the metal ion. Through the calculation of the SternâVolmer quenching constant, it was determined that the 1:1 binding model is applicable. This research underscores the potential of UVâVis absorption spectroscopy as a highly sensitive method for detecting metal ions. By elucidating the synthesis, photophysical behavior, and metal ion interaction of thiazolidine-based CILs, this study contributes valuable insights into the field of functionalized ionic liquids and their potential applications in various areas
Symmetrical and Asymmetrical Cyanine Dyes. Synthesis, Spectral Properties, and BSA Association Study
New cyanines were prepared by an
efficient and practical route
with satisfactory overall yield from low-cost starting materials.
The photophysical behavior of the cyanines was investigated using
UVâvis and steady-state fluorescence in solution, as well as
their association with bovine serum albumin (BSA) in phosphate buffer
solution (PBS). No cyanine aggregation was observed in organic solvents
or in phosphate buffer solution. The alkyl chain length in the quaternized
nitrogen was shown to be fundamental for BSA detection in PBS in these
dyes
Synthesis of Amino Acid-Derived 1,2,3-Triazoles: Development of a Nontrivial Fluorescent Sensor in Solution for the Enantioselective Sensing of a Carbohydrate and Bovine Serum Albumin Interaction
A series
of amino acid-derived 1,2,3-triazoles presenting the amino
acid and the aromatic moieties connected by a triazole-4-carboxylate
spacer is discussed in this work. These compounds were achieved in
good yields by organocatalytic enamineâazide [3 + 2] cycloadditions.
One of the molecules obtained, bearing a 7-chloroquinoline moiety,
was photoactive in the UV-violet region and was successfully employed
as a probe for substrate-specific enantiomeric sensing using d-(â)-arabinose and l-(+)-arabinose. The potential
application as a fluorescent probe to detect protein in phosphate
buffer solution was also explored using as model bovine serum albumin
(BSA). The studied compounds presented both suppression and association
behavior in the presence of BSA. In addition, theoretical calculations
were performed at levels ÏB97XD/cc-pVDZ and PBE1PBE/6-311+GÂ(d,p)
together with the polarizable continuum model to understand the interaction
of the molecules with the enantiomers
Electrochemical diselenation of BODIPY fluorophores for bioimaging applications and sensitization of 1O2
We report a rapid, efficient, and scope-extensive approach for the late-stage electrochemical diselenation of BODIPYs. Photophysical analyses reveal red-shifted absorption - corroborated by TD-DFT and DLPNO-STEOM-CCSD computations - and color-tunable emission with large Stokes shifts in the selenium-containing derivatives compared to their precursors. In addition, due to the presence of the heavy Se atoms, competitive ISC generates triplet states which sensitize 1O2 and display phosphorescence in PMMA films at RT and in a frozen glass matrix at 77 K. Importantly, the selenium-containing BODIPYs demonstrate the ability to selectively stain lipid droplets, exhibiting distinct fluorescence in both green and red channels. This work highlights the potential of electrochemistry as an efficient method for synthesizing unique emission-tunable fluorophores with broad-ranging applications in bioimaging and related fields