Solver pro

In order to analyze the formation of HEP/VEGF-SNCs on the bone substitutes, samples were fixed with 4% paraformaldehyde (PFA) for 10 min at 4 °C. After dehydration, the specimens were observed by mean of SEM (either with Hitachi TM1000 or FEG Sirion XL; FEI) in conventional high vacuum mode with a secondary electron detector. A commercial stand-alone AFM microscope Solver Pro (Nt-Mdt Inc., Moscow, Russia) was used to acquire AFM images. Tapping imaging mode was used, with NSG 10 cantilever with a typical resonance frequency of 105 kHz, and a spring constant of 2 N m⁻¹. The image resolution was set to 512 × 512, with a scanning rate of 1 Hz. Images were analyzed using the open source software Gwyddion 2.24 [52 (link)].

An AFM (Solver PRO, NT-MDT, Moscow, Russia) was used to characterize the topology of the samples. Pieces approximately 4 mm × 4 mm in size and 1 mm in thickness were excised from the surface of treated and untreated cloves while using a scalpel and mounted onto aluminum holders using carbon tape. All of the measurements were performed in tapping mode using ATEC-NC-20 tips (Nano and More GmbH, Wetzlar, Germany) with a resonance frequency of 210–490 kHz and the force constant of 12–110 N/m.

Atomic force microscopy (Solver-PRO, NT-MDT, Moscow, Russia) was used to estimate the surface roughness of the graphene channel. The quality of FET channels was investigated by microRaman spectroscopy (Centaur HR, Nanoscan Technology, Dolgoprudny, Moscow region, Russia) with a 100× objective (NA = 0.9) at a 532 nm wavelength with a laser power of 0.5 mW. Current voltage characteristics (CVC) were measured using Ag/AgCl (Science Products GmbH) as a liquid gate electrode with a semiconductor parameter analyzer IPPP1/5 (MNIPI, Minsk, Belarus) connected to the source and drain electrodes.
The NT-proBNP was dissolved in 0.1×PBS with the addition of Tween (0.01%) to avoid sticking of proteins to the tube wall. Solutions of biomarker were prepared of different concentrations from 1 fg/mL to 10 ng/mL [21 (link)]. Artificial saliva (AS) was ordered from “Apoteka Beograd” (Belgrade, Serbia) and dissolved 10 times in 0.01×PBS. NT-proBNP was dissolved in AS the same way as described above for PBS.

The surface morphology of the samples was analyzed with an AFM (Solver PRO, NT-MDT, Moscow, Russia). Images were recorded in a tapping mode using ATEC-NC-20 tips (Nano And More GmbH, Germany). A resonance frequency of the tip and the force constant were 210–490 kHz and 12–110 Nm⁻¹, respectively. An average surface roughness of the samples (Ra) was determined by using the program Spip 5.1.3 (Image Metrology A/S). The average surface roughness was calculated from the images taken over an area of 5 × 5 µm².

The surface morphology was examined by Atomic Force Microscopy (AFM). An AFM (Solver PRO, NT-MDT, Moscow, Russia) was used to determine variations of the surface morphology and roughness around the center of the impact point of the plasma jet with the polymer surface. The measurements were performed in the semi-contact mode. Images with a size of 2 × 2 µm² were recorded.