Preparation of fluorescently and magnetically visualized nanodiamond stably dispersed under physiological environment for their practical use as a biological multi-modal imaging probe

摘要

Fluorescent nanodiamond (f-ND) with 30 nm in diameter was prepared by immobilization of fluorescent tag (fluorescein) through (O-aminododecanoate linkage, while fluorescein was not introduced sufficiently on the surface of amino ND (ND-NH2). The linker was covalently bound on the surface of the NDs through ester group by radical reaction of hydrogenated nanodiamonds (ND-H) and ω-aminododecanoic acid in the presence of benzoyl peroxide. When BOC (tert-butoxycarbonyl)-protected ω-aminododecanoic acid was employed, the coverage of the linker on the ND surface enhanced remarkably, resulting in brighter luminescent from the ND. Thus prepared f-NDs were successfully observed by fluorescent microscopy.