NANOPARTICLES FOR BIOIMAGING IN REGENERATIVE MEDICINE - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 858

peroxide in physiology and numerous diseases is being increasingly
recognized. The development of fluorescent probes for the selec-
tiveandsensitivedetectionofhydrogenperoxideisnowbeingener-
getically undertaken. Recently, several novel fluorescent probes for
the selective detection of hydrogen peroxide have been developed,
and some of them have been applied to the imaging of intracellu-
larhydrogenperoxide.Mostoftheseapproachesforselectivehydro-
genperoxideimagingarebasedonthechemoselectivedeprotecting
groups, which can becleaved by hydrogen peroxide selectively. 1 - 3
Maeda et al . synthesized pentafluorobenzenesulfonyl fluores-
ceins for the selective detection of hydrogen peroxide (Fig. 42.2).
These probes are deprotected by hydrogen peroxide oxidation
to release free fluorescent fluorescein. Unlike fluorescein with
a dinitrobenzenesulfonate-leaving group, these probes selectively
reactwithhighselectivitytohydrogenperoxide,whosereactionrate
constant is up to ∼ 250M - 1 s - 1 . 24 These probes were synthesized
on the basis of the following rationale that the pentafluorobenzene
ring enhances the reactivity of sulfonates toward hydrogen perox-
ide. They exhibited excellent selectivity to hydrogen peroxide over
hydroxy radicals and superoxide. The detection limit of the probe
(X=F) was reported to be4.6 pmol.
Chang et al. designedandsynthesizedvariousfluorescentprobes
using chemoselective boronate deprotection. The major strategy
of these optical probes involves exploiting the selective hydrogen
peroxide-mediated transformation of arylboronates to phenols. 1 - 3
Upon the reaction with hydrogen peroxide, hydrolytic deprotection
of the boronates produces the fluorescent fluorescien product. One
of examplesisshown in Fig. 42.3.
Figure 42.2. Hydrogen peroxide imaging based on benzenesulfonyl
protection.