Zetasizer 3000hs

Different aqueous dispersions of SWCNTs were dispersed onto holey carbon film on copper grids. The sample morphologies were observed by transmission electron microscopy (TEM, JEM-200CX).
To determine particle size and zeta potential, a sample of 200 μL (with a concentration of 50 μg·mL⁻¹) was dispersed in deionized water to a final volume of 3 mL. Particle size and zeta potential were measured using laser particle analysis (Malvern Zetasizer 3000HS). A volume-weighted Gaussian size distribution was fit to the autocorrelation functions to obtain the particle size and zeta potential values.
The atomic fractions of C, O, and N in the different SWCNTs samples were determined by X-ray photoelectron spectroscopy (XPS, Thermo Fisher Scientific). Fourier-transform infrared (FTIR) spectra in the range from 500 to 4000 cm⁻¹ were recorded with a FTIR spectrometer (Nicolet IS10). X-ray diffraction (XRD) analysis was conducted using a BRUKER D8 X-ray diffractometer in the 2θ range of 0–100° at a scanning rate of 5°·min⁻¹.
For atomic force microscopy (AFM) measurements, different SWCNT dispersions (ethanol/ultrapure water = 1:1) with a concentration of 0.01% were dripped on freshly cleaved mica and observed using an AFM (Dimension Icon, Bruker AXS).

The average particle sizes and surface charges of naked Ad or Ad nanocomplexes (Ad/P₅N₅LG, Ad/P₅N₂LG-FA, or Ad/P₅N₅LG-FA formed with Ad:polymer molar ratio of 5 × 10⁵) were determined by the Zetasizer 3000HS (Malvern Instrument Inc., Worcestershire, UK) with a He-Ne Laser beam (633 nm, fixed scattering angle of 90°) at room temperature. The surface charges of the nanomaterials (P₅N₅LG, P₅N₂LG-FA, and P₅N₅LG-FA) were measured by Zetasizer 3000HS as described above. The obtained sizes and surface charges are the average values of 3 runs for independently prepared triplicate of each sample.

The Z-Average size and zeta potential of DSF loaded mPEG-PLGA nanoparticles (DFSNPs) suspended in water were determined using dynamic light scattering (Zetasizer 3000HS, Malvern Instruments Ltd, UK). The particle size was determined using a He-Ne laser beam at a wavelength of 633 nm with a fixed scattering angle of 90° at 25°C. The data for a mean value for the size (z-Average) and a width parameter, Polydispersity Index (PDI) was evaluated using cumulants analysis. The PDI is a dimensionless, simple 2-parameter fit to the cumulants analysis and indicates the deviation of the measured autocorrelation function during the particle size estimation from that of monodisperse spheres having the same diameter. The PDI values range from 0 to 1. The zeta potential values were measured by laser Doppler velocimetry at 25°C at the default parameters of the dielectric constant, refractive index, and viscosity of water, using a disposable capillary cell with a volume of 1 mL. The morphology of the mPEG-PLGA nanoparticles was examined by transmission electron microscopy (Hitachi H-9500, Hitachi High Technologies America, Inc. Dallas, TX). Freeze-dried nanoparticles were dissolved in water with 0.05% Tween-80, and a small droplet was placed on a carbon-coated copper grid, followed by drying at room temperature before measurements were taken.