Model su 70

The crystalline structure was characterized by powder X-ray diffraction (PXRD; DMAX-2500PC). The micromorphology was obtained by using the field-emission scanning electron microscopy (FE-SEM; Hitachi Model SU-70) coupled with an energy-dispersive X-ray spectroscopy (EDS; X-max), and the high-resolution transmission electron microscopy (HR-TEM; JEM-F200). The contents of carbon were evaluated by thermogravimetric analysis (TGA; HCT-1). The Raman spectra were obtained through a Raman spectrometer (Horiba LabRAM HR). N₂ absorption–desorption isotherms were recorded by a chemisorption analyzer (Quantachrome Autosorb IQ). The specific surface area and pore-size distribution were calculated by the Brunauer–Emmett–Teller model and Barrett–Joyner–Halenda method, respectively. The surface electronic properties were investigated by X-ray photoelectron spectroscopy (XPS; Thermo ESCALAB 250XI). The Fourier transform infrared (FT-IR) spectra were recorded by a FT-IR spectrometer (VERTEX-70). The conductive properties were recorded by Hall Effect Measurement System (Ecopia HMS-5000). The electromagnetic parameters in the 2.0 − 18.0 GHz were measured by a vector network analyzer (VNA; Agilent PNA N5244A).

SEM analysis was performed as described by Ceresa et al. [26 (link)], with minor modifications. Briefly, titanium discs with surface biofilm were washed three times with PBS and fixed in glutaraldehyde solution (2.5% w/v, Sigma) for 2 h at 4 °C. Then, the glutaraldehyde solution was removed, and the specimen was washed three times with PBS for 5 min. Osmium tetroxide solution (1% w/v, Sigma) was added to the samples for 1 h at 25 ℃ and rinsed twice (PBS and DW each) for 5 min. After fixation, the titanium discs with biofilms were dehydrated in a graded ethanol series (50%, 60%, 70%, 80%, 90%, and 100%) for 10 min each. For substitution, hexamethyldisilazane (Sigma) was added twice for 10 min. After drying overnight, samples were sputter-coated with gold and observed using SEM (Hitachi, Model: SU-70, Tokyo, Japan) at an accelerating voltage of 15.0 kV.

Two millilitres of living culture was gently filtered onto 1 cm diameter, 1 µm pore size, Nucleopore polycarbonate filters, rinsed with distilled water to remove salt crystals, and the filters gently air dried. Filters were mounted on aluminium stubs, sputter-coated with platinum, and analysed using an Emission SEM (Model Su-70, Hitachi, Tokyo, Japan).