Lb 550

Liposome preparations’ hydrodynamic radius at 25 °C was obtained by DLS (Nanoparticle Size Analyzer, Horiba Jobin Yvonne LB-550, Horiba Jobin Yvon SRL, Opera Milano, Italy), with 100 samplings per measurement. The power spectrum (PS) obtained by fast Fourier transformation of the light intensity fluctuations was converted into particle size distribution by comparing it, using the Twomey method [27 (link)], with the calculated frequency distribution based on the Brownian movement for particles of different size.

The particle size distribution of liposomes was determined using a dynamic light scattering instrument (LB-550, Horiba Ltd., Kyoto, Japan). Liposomal dispersions were diluted with double-distilled water to ensure the light scattering intensity in the instrument’s sensitivity range. The stability of the liposomal formulations was evaluated after storage at 4 °C for 1, 7 and 14 days. All measurements were taken in triplicate.

UV-vis spectroscopy was performed on the aqueous dispersions of AuNPs, in quartz cuvettes with 1 and 0.1 cm optical path length, in the wavelength range 200–700 nm, at 25 °C, with a spectral resolution of 1 nm on a Perkin Elmer UV-vis spectrometer (Lambda 2S, Waltham, MA, USA). Samples were pre-equilibrated prior to the initial scan for 2 min at RT. Particle size analysis was performed by dynamic light scattering (Horiba LB-550, Kyoto, Japan) and the results were presented as the mean of at least three measurements.

The particle size distribution and morphology of the NaYF₄ NPs were evaluated via TEM (HD-2300, Hitachi, Japan) with accelerating voltage of 200 kV. The crystalline phase of the NaYF₄ NPs was evaluated via XRD (RINT-TTR III, Rigaku, Japan). The hydrodynamic diameters of the NaYF₄ NPs samples (solvent: cyclohexane, concentration: 2 mg/mL, room temperature) were determined using a dynamic light scattering particle size analyzer (LB-550; Horiba, Ltd., Kyoto, Japan).

Particle size measurements and size distribution of the composite nanoparticles were studied by dynamic light scattering technique (DLS) using a dynamic light scattering particle size analyzer Horiba LB-550 apparatus equipped with a diode laser with a wavelength of 650 nm and working at an angle of 90° and temperature 25 °C. The analysis was performed right after the preparation of the nanoparticle dispersions according to Ali et al.^{48 (link)}. The zeta potential and size distribution of nano-TiO₂ before and after modification were determined by the DLS method by using an SZ-100 Zetasizer (Malvern). Before, the samples were dispersed in distilled water according to Nguyen et al.^{49 (link)}.