1 research outputs found
Boronic Acid Functionalized Boron Dipyrromethene Fluorescent Probes: Preparation, Characterization, and Saccharides Sensing Applications
Fluorescent probes based on boron dipyrromethene functionalized
with a phenylboronic acid group (BODIPY–PBAs) were synthesized
in high yield for the first time by Suzuki coupling of bisÂ(pinacolato)Âdiboron
and 8-(4-bromophenyl)-1,3,5,7-tetramethyl-4,4-difluoro-4-bora-3a,4a-diaza-<i>s</i>-indacene (BODIPY). Wavelength tuning of the fluorophores
was achieved by attaching an auxochromic substituent to the 5-position
of the BODIPY core structure through Knoevenagel condensation. The
emission intensity of fluorophores increases when binding to the analytes
with diol groups and forming boronic esters at fixed pH. These compounds
can detect monosaccharides in the concentration range of 0.1–100
mM. Whereas glycogen was found to quench the fluorescence of BODIPY–PBAs
in an aqueous solution due to the self-quenching of the fluorophores
after attaching in the extensively branched and compact glucose polymer,
further addition of d-fructose to the solution can release
the fluorophores from the polymer and the fluorescence regains. The
BODIPY–PBA fluorophore has been applied in polymeric optodes
containing anion exchangers to perform repetitive measurement. Such
sensors respond to different monosaccharides in the range of 0.1–100
mM and demonstrate an improved selectivity toward d-fructose
over other saccharides, compared to the results obtained from homogeneous
assay