NPs were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), and electrophoretic light scattering (ELS). All dispersions of NPs were diluted 10 times before to be applied to a carbon film-covered copper grid. PTA solution (1% w/v) was used as contrast color. The samples were dried and then examined under a TEM JEOL 1010 electron microscope and photographed at an accelerating voltage of 64 kV.
DLS and ELS analyses were performed with a Zetasizer Nano series ZS90 (Malvern Instruments, Malvern, UK) equipped with a JDS Uniphase 22mW He-Ne laser operating at 632.8 nm, an optical fiber-based detector, a digital LV/LSE-5003 correlator, and a temperature controller (Julabo water bath) set at 25°C.
The hydrodynamic diameter of the particles (Zh) and the particle size distribution (polydispersity index, PDI) were analyzed using the ALV-60X0 software V.3.X provided by Malvern. The ζ potential, indicating the electric charge on the NPs surface and the physical stability of the formulations, was calculated by the Helmholtz-Smoluchowsky equation using the same instrument.
DLS and ELS analyses were performed with a Zetasizer Nano series ZS90 (Malvern Instruments, Malvern, UK) equipped with a JDS Uniphase 22mW He-Ne laser operating at 632.8 nm, an optical fiber-based detector, a digital LV/LSE-5003 correlator, and a temperature controller (Julabo water bath) set at 25°C.
The hydrodynamic diameter of the particles (Zh) and the particle size distribution (polydispersity index, PDI) were analyzed using the ALV-60X0 software V.3.X provided by Malvern. The ζ potential, indicating the electric charge on the NPs surface and the physical stability of the formulations, was calculated by the Helmholtz-Smoluchowsky equation using the same instrument.