Preparation and fluorescence properties of fluorophore-labeled avidin-biotin system immobilized on Fe3O4 nanoparticles through functional indolequinone linker.
We prepared and characterized a new class of fluorophore-labeled magnetic nanoparticles (MNPs) possessing a hypoxia-responsive unit to construct a hypoxia-selective emission system. The indolequinone derivative as a hypoxia-response unit bearing biotin was synthesized and immobilized on Fe(3)O(4) MNP. Subsequent complexation of this functionalized MNP with fluorescein-labeled avidin formed fluorophore-labeled nanoparticles (AF-QB@MNP). The fluorescence intensity of AF-QB@MNP was suppressed because of the adjacent quenching function of the indolequinone moiety and MNP. Upon hypoxic treatment by NADPH:cytochrome P450 reductase, AF-QB@MNP was activated to liberate a fluorescence unit, leading to the significant enhancement of fluorescence emission, while a smaller enhancement in fluorescence emission occurred upon aerobic treatment. The AF-QB@MNP has a indispensable properties as a fluorescent probe for imaging of disease relevant hypoxic microenvironments.
Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura Campus, Kyoto 615-8510, Japan.
Nao
N
Hirata
Kazuhito
K
Tanabe
Asako
A
Narita
Kazuo
K
Tanaka
Kensuke
K
Naka
Yoshiki
Y
Chujo
Sei-ichi
S
Nishimoto
D001360:Avidin / Q000737:chemistry*; D001710:Biotin / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry*; D005452:Fluoresceins / Q000737:chemistry*; D005456:Fluorescent Dyes; D000860:Hypoxia; D045563:Indolequinones / Q000737:chemistry*; D008280:Magnetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction
D003432:Cross-Linking Reagents; D005290:Ferric Compounds; D005452:Fluoresceins; D005456:Fluorescent Dyes; D045563:Indolequinones; C049445:fluorescein-avidin; D001360:Avidin; D001710:Biotin