Inorganic mercury detection and controlled release of chelating agents from ion-responsive liposomes.

A liposome system that can detect and detoxify mercury in aqueous solution is demonstrated. The system consists of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine and 20% PEG-PE (PEG MW 2000 Da) that forms liposome, which encapsulates self-quenching fluorescein for detection, and chelating agent meso-2,3-dimercaptosuccinic acid (meso-DMSA) for chelating detoxification through Hg(2+)-responsive release of fluorescein and meso-DMSA. This system can detect mercury levels as low as 10 nM with high selectivity.

MRI detection of thrombin with aptamer functionalized superparamagnetic iron oxide nanoparticles.

Design of smart MRI contrast agent based on superparamagnetic iron oxide nanoparticles and aptamers has been described for the detection of human alpha-thrombin protein. The contrast agent is based on the assembly of the aptamer functionalized nanoparticles in the presence of thrombin. A detectable change in MRI signal is observed with 25 nM thrombin in human serum.