Zetasizer nano series equipment

Biogenic silver nanoparticles were synthesized using a 4-step process: 1) hesperetin was dissolved in alkaline solution (sodium hydroxide, NaOH, 0.005 mol L⁻¹) to a final 1 mmol L⁻¹ concentration, 2) a solution of silver (I) nitrate (1 mmol L⁻¹) was added dropwise to a hesperetin solution in a 1:1 (v v⁻¹) ratio, and then the 3) colloid pH of 7.4 was reached using a diluted solution of hydrochloric acid (HCl 0.05 mol L⁻¹). The average hydrodynamic diameter of nanoparticles was determined by Dynamic Light Scattering (DLS) and the surface charge was measured in a Zetasizer Nano series equipment (Malvern Instruments). The potential was measured by electrophoretic mobility using dispersions of nanoparticles in a KCl (USB) solution at 1.0 mmol L⁻¹ concentration and a Zetasizer Nano ZS analyzer (Malvern Instruments Corp., Malvern, United Kingdom). The AgNP@HST morphology was evaluated by Transmission Electron Microscopy (TEM). After 1:100 (v v⁻¹) dilution of 0.5 mmol ml⁻¹ of colloid silver nanoparticles in water, samples were deposited on carbon-coated film supported in 400 mesh copper grids (Ted Pella) and observed using a Libra 120 (Zeiss) microscope equipped with a spectrometer in-column “omega” and imaging system Olympus (OSIS), with Cantega G2 camera and iTEM software.

Dynamic light scattering (DLS) was used to determine the average liposome size in a Malvern Zetasizer Nano-series equipment (Malvern Instruments Zen 600, Malvern, UK). Aliquots from PC, PCPG5% e PCPG10% (with or without ASTA) stock solutions were diluted to a final concentration of 1 mM total phospholipid in 50 mM phosphate buffer, pH 7.4, at 25 °C. To check ASTA incorporation into liposome membranes laser with λ = 590 nm was used.

The zeta potential study was used to quantify the loading surface of the adsorbents (HA, HAS, and ACB) at a concentration of 1.0 mg mL⁻¹ and 25°C for each of the pH buffer. The values of the zeta potential adsorbents were quantified using (6) of Smoluchowski [23 ]. This was done by applying the integrated computational procedure through the Zeta Sizer Nano series equipment ZS from Malvern 3600 Instruments®. The electrophoretic mobility of the particles being measured was evaluated and converted into zeta potential values expressed in mV based on the pH: $\begin{array}{c}Zp=\frac{\mathrm{4}·\pi ·v_t}{D_t}\times E_m,\end{array}$ where E_m is electrophoretic mobility; v_t is suspending liquid viscosity (poise) at room temperature; D_t is dielectric constant; Zp is voltage (mV).