Type e scanner head

The sizes and morphologies of nanomaterials were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). SEM samples were prepared by depositing the above-prepared samples onto conductive glass, following by drying, washing with double-distilled H₂O (diH₂O) and further drying. Samples were coated with Au (5 nm) by spray, and observed on an S-4800 scanning electron microscope. For AFM of hNVs, samples (10 μL) were casted on freshly peeled mica substrate, followed by drying, rinsing, and dehumidifying. AFM was carried out in tapping-mode in air on a PicoForce Multimode AFM (Bruker, CA) equipped with a Nanoscope® V controller, a type E scanner head, and an OTESPA (Bruker, CA) AFM cantilever. AFM images were then analyzed by Nanoscope Software (ver. 7.3–8.15, Bruker, CA). The sizes of hNVs suspended in Dulbecco’s PBS were also characterized using dynamic light scattering (DLS) on a Nanoparticle Analyzer (HORIBA Scientific, Tokyo, Japan). Bright field or fluorescence images of fluorophore-labeled hNVs were taken on a Zeiss LSM 780 confocal microscope (Chesterfield, VA).