Microfluidic-Based Synthesis of Magnetic Nanoparticles Coupled with Miniaturized NMR for Online Relaxation Studies

作者：Bemetz Jonas; Wegemann Andreas; Saatchi Katayoun; Haase Axel; Hafeli Urs O; Niessner Reinhard; Gleich Bernhard; Seidel Michael^*

来源：Analytical Chemistry, 2018, 90(16): 9975-9982.

DOI：10.1021/acs.analchem.8b02374

Using compact desktop NMR systems for rapid characterization of relaxation properties directly after synthesis can expedite the development of functional magnetic nanoparticles. Therefore, an automated system that combines a miniaturized NMR relaxometer and a flow-based microreactor for online synthesis and characterization of magnetic iron oxide nanoparticles is constructed and tested. NMR relaxation properties are quantified online with a 0.5 T permanent magnet for measurement of transverse (T-2) and longitudinal (T-1) relaxation times. Nanoparticles with a primary particle size of about 25 nm are prepared by coprecipitation in a tape-based microreactor that utilizes 3D hydrodynamic flow focusing to avoid channel clogging. Cluster sizes are expeditiously optimized for maximum transverse relaxivity of 115.5 mM s(-1). The compact process control system is an efficient tool that speeds up synthesis optimization and product characterization of magnetic nanoparticles for nanomedical, theranostic, and NMR-based biosensing applications.

• 出版日期2018-8-21