Libra 200 fe hr transmission electron microscope

SeNPs were fabricated from a solid Se⁰ target (Sigma Aldrich, Burlington, Massachusetts, USA) by laser ablation with subsequent fragmentation in water with 1060–1070 nm Ytterbium-doped fiber laser (YLPM-1). Laser pulses had an average power of 20 mV, duration of 80 ns and frequency of 20 kHz. The characteristics of acoustic oscillations (breakdown shockwave amplitude) and generated plasma (average distance between optical breakdowns in a track) were registered in the experimental cell during laser fragmentation to examine NPs size evolution. After fragmentation, the hydrodynamic diameter and ζ-potential of obtained SeNPs were measured with Zetasizer Ultra Red Label (Malvern Panalytical, Malvern, UK). The diameter of dried SeNPs was evaluated with a Libra 200 FE HR transmission electron microscope (Carl Zeiss, Oberkochen, Germany). More detailed descriptions can be found in previous works [42 (link),43 (link)].

The method of laser ablation in a liquid was used for the synthesis of the ZnO-NPs. A pulsed ytterbium-doped fiber laser was used. Laser radiation parameters: λ = 1064 nm, τ = 4–200 ns; ν = 20 kHz; average power up to 20 W; E = 1 mJ. The liquid layer (0.05 M NaNO₃ aqueous solution) over the target (metal zinc plate) was about 1 mm. Irradiation time varied in the range of 5–20 min. Using the Zetasizer Ultra Red Label (Malvern Panalytical Ltd., Malvern, UK), the hydrodynamic diameter (DLS) and the zeta potential (ELS) of the obtained NPs were determined. The NP diameter was confirmed using a CPS 24000 (CPS Instruments, Prairieville, LA, USA) [61 (link)]. The morphological features (shape, topology) and the elemental composition of the NPs, were studied using a Libra 200 FE HR transmission electron microscope in combination with a JED-2300 energy dispersive X-ray spectrometer (Carl Zeiss, Jena, Germany). The composition of the obtained colloidal solutions of NPs was confirmed using Cintra 4040 (GBC Scientific Equipment, Braeside, Australia). Samples preparation for TEM was performed according to the following protocol. A gold mesh Ø ~4 mm was placed in a titanium holder. Samples of ZnO-NPs colloids were applied to the grid as 0.25 µL drops. The samples were dried at room temperature for 10 min with subsequent evacuated.

Gold nanoparticles (AuNPs) are obtained by laser ablation of a massive target in deionized water. The massive target made of pure gold (99.999%) was placed at the bottom of an experimental glass cell under a 2 mm layer of deionized water. Ablation was performed using Nd:YAG laser radiation (90 J/cm², wavelength 1064 nm, pulse duration 10 ns, repetition rate 8 kHz) [36 (link)]. The laser radiation was mixed over the surface of the massive target using a 2D electro-galvanic scanner (Atko, Moscow, Russia) so that each new pulse did not overlap with the previous one [37 (link)]. The morphology of the nanoparticles was studied using a Libra 200 FE HR transmission electron microscope (Carl Zeiss, Jena, Germany).