Applications of Thermoresponsive Magnetic Nanoparticles

Figure 3

Separation and enrichment of a model protein using thermoresponsive MNPs and Au nanoparticles. Au nanoparticles functionalized with a thermoresponsive block polymer, PNIPAAm-b-P DMAEAm, were conjugated to biotin molecules to capture streptavidin from spiked human plasma. Capture of streptavidin was carried out by incubation of the plasma with PNIPAAm-b-PDMAEAm-Au, PNIPAAm-MNP, and free PNIPAAm followed by magnetic separation above LCST (45°C). After removing supernatant, the sample was dissolved in buffer below LCST which caused dispersion of assembly, and streptavidin was still bound to Au nanoparticles. The sample was directly applied to lateral flow assay which contained anti-streptavidin antibody for detection of streptavidin (reprinted with the permission of publisher, American Chemical Society, copyright 2010, from [70]).