Bioinspired magnetite crystallization directed by random copolypeptides

Autor: Jos J. M. Lenders, Harshal R. Zope, Ayana Yamagishi, Paul H. H. Bomans, Atsushi Arakaki, Alexander Kros, Gijsbertus de With, Nico A. J. M. Sommerdijk
Přispěvatelé: Materials and Interface Chemistry
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: Advanced Functional Materials, 25(5), 711-719. Wiley-VCH Verlag
Advanced Functional Materials
ISSN: 1616-3028
1616-301X
Popis: Control over magnetite (Fe 3 O 4 ) formation is diffi cult to achieve in synthetic systems without using non-aqueous media and high temperatures. In contrast, Nature employs often intrinsically disordered proteins to tightly tailor the size, shape, purity, and organization of the nanocrystals to optimize their magnetic properties. Inspired by such “fl exible polyelectrolytes,” here random copolypeptides having different amino acid compositions are used as control agents in the bioinspired coprecipitation of magnetite through a ferrihydrite precursor, following a recently developed mineralization protocol. Importantly, the copolypeptide library is designed such that the amino acid composition can be optimized to simultaneously direct the size of the nanoparticles as well as their dispersibility in aqueous media in a one-pot manner. Acidic amino acids are demonstrated to regulate the crystal size by delaying nucleation and reducing growth. Their relative content thus can be balanced to tune between the superparamagnetic and ferrimagnetic regimes, and high contents of negatively charged amino acids result in colloidal stabilization of superparamagnetic nanoparticles at high pH. Conversely, with positively charged lysine-rich copolypeptides ferrimagnetic crystals are obtained which are stabilized at neutral pH and self-organize in chains, as visualized by cryotransmission electron microscopy. Altogether, the presented fi ndings give important insights for the future development of additive-mediated nanomaterial syntheses.
Databáze: OpenAIRE
Externí odkaz: