Characterization of iron oxide NWs used in this study. (A) Physicochemical properties of NWs. Size distribution of non-functionalized NWs measured by DLS at 25 C. PdI - polydispersity index. Error bars represent standard deviation (n = 3). TEM image of non-functionalized NWs (scale bar is 100 nm, magnification 160,000 ×). Average diameter calculation was based on DLS (n = 3); zeta potential was measured with NWs functionalized with linTT1 peptide (n = 3); the amount of peptide is given as μmol/g of iron. (B) Binding of FAM-labeled linTT1-NWs, RPARPAR-NWs or control FAM-NWs to recombinant p32. Thirty μg/ml of NWs were incubated with immobilized his-tagged p32 for 1 h, followed by washes to remove unbound NWs and quantification of bound FAM-NWs by spectrometry. Y axis is the NW fluorescence in arbitrary units (a.u.). N = 3; statistical analysis by one-way ANOVA; error bars, mean + SEM, ***p < 0.001.