KCS

Silica nanoparticles have garnered attention as promising biomedical probes for hyperpolarized 29Si magnetic resonance imaging and spectroscopy. We have demonstrated a straightforward method of synthesizing selectively 29Si enriched nano-sized silica particles with high degrees of control in terms of the particles’ physicochemical properties and size. By utilizing 100% 29Si enriched TEOS, a silica precursor, selective enrichments on either particle surface (10 nm thickness) or core (40 nm diameter) were precisely conducted. With the particles of various structural characteristic, dynamic nuclear polarization (DNP) properties ranging from buildup, enhancement factor, and depolarization time at a cryogenic temperature were examined. The best considerable signal amplification was achieved from the silica nanoparticle with a selective enrichment localized on the particle surface, exposing both the successive surface polarization and polarization profile. The synthetic strategy with selective enrichments on the particles may expand the practical applicability of the nano-sized silica materials in various biomolecular processes, including targeted molecular imaging in vivo.