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Cell Labeling and Targeting with Superparamagnetic Iron Oxide Nanoparticles
Published on: October 19, 2015
Drawing with Iron on a Gel Containing a Supramolecular Siderophore
Songjun Xiao1, Paul J Paukstelis1, Richard D Ash2
1Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742, USA.
Abstract:
Guanosine-5'-hydroxamic acid (3) forms hydrogels when mixed with guanosine (1) and KCl. The 5'-hydroxamic acid (HA) unit is pH-responsive and also chelates Fe3+ . When gels are prepared under basic conditions, the 5'-HA groups are deprotonated and the anionic hydrogel binds cationic thiazole orange (TO), signaled by enhanced fluorescence. The HA nucleoside 3, when immobilized in the G-quartet gel, acts as a supramolecular siderophore to form red complexes with Fe3+ . We patterned the hydrogel's surface with FeCl3 , by hand and by using a 3D printer. Patterns form instantly, are visible by eye, and can be erased using vitamin C. This hydrogel, combining self-assembled G-quartet and siderophore-Fe3+ motifs, is strong, can be molded into different shapes, and is stable on the bench or under salt water.
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