Electrochemical preparation and characterization of magnetic core-shell nanowires for biomedical applications

Abstract

Magnetic CoNi@Au coreshell nanorods have been electrochemically synthesized, characterized and functionalized to test their inherent cytotoxicity in order to assess their potential use for biomedical applications. The initially electrodeposited CoNi nanorods have been covered with a gold layer bymeans of galvanic displacement to minimize the nanowires toxicity and their aggregation, and favour the functionalization. The presence of a gold layer on the nanorod surface slightlymodifies themagnetic behaviour of the asdeposited nanorods, maintaining their softmagnetic behaviour and high magnetization of saturation. The complete covering of the nanorodswith the gold shell favours a good functionalization with a layer of (11Mercaptoundecyl) hexa(ethylene glycol)molecules, in order to create a hydrophilic coating to avoid the aggregation of nanorods, keeping themin suspension and give them stability in biological media. The presence of the organic layer incorporated was detected by means of electrochemical probe experiments. A cytotoxicity test of functionalized coreshell nanorods, carried out with adherent HeLa cells, showed that cell viability was higher than 80% for amounts of nanorods up to 10 μgmL−1. These results make functionalized nanorods promising vehicles for targeted drug delivery inmedicine, which gives a complementary property to the magnetic nanoparticles. © 2015 Elsevier B.V. All rights reserved.