Jem 2100 analytical electron microscope

The morphology of the as-prepared pGNR@MSN was characterized employing high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and high-resolution transmission electron microscopy (HRTEM) using a JEM-2100 analytical electron microscope (JEOL Ltd., Tokyo, Japan). The crystal structure of the GNRs was measured using X-ray diffraction (XRD; X'Pert PRO MPD, Hol-land Panalytical) with a monochromatic X-ray beam and nickel-filtered Cu Ka radiation and the Fourier transform infrared (FT-IR) spectra of the pGNR@MSN were recorded using a FT-IR spectrometer (Nicolet IS50-Continuum; Thermo Fisher Scientific, Waltham, MA, USA). In addition, the N₂ adsorption–desorption isothermal curve was recorded using the TriStar II 3020 system (Micromeritics, USA), and the zeta potential and particle size of the nanoparticles were determined using a Zetasizer Nano ZS90 analyzer (Malvern Panalytical, Malvern, Netherland).

The samples were characterized by Fourier transform infrared spectroscopy (FT-IR) using a Perkin Elmer 1600 FTIR spectrometer (Perkin Elmer Waltham, MA, USA) and scanned over the wave number range between 400 and 4000 cm⁻¹.
The surface morphology of the modified electrodes was characterized by the use of a ZEISS EVO MA 25 (Carl Zeiss S.A.S. Rueil-Malmaison, France) scanning electron microscope (SEM). HR-TEM images were obtained using a JEM-2100 analytical electron microscope (JEOL Europe S.A.S., Croissy-sur-Seine, France) operating at an accelerating voltage of 200 kV. For HR-TEM images, the CuNPs/MIP-OPPy composite was transferred from the electrode surface to the TEM grid.
Electrochemical measurements were carried out using an Autolab electrochemical analyzer, model PGSTAT 302N (Eco Chemie, Utrecht, The Netherlands). A three-electrode system was employed, consisting of a glassy carbon working electrode (GCE, diameter 3 mm), an Ag/AgCl/KCl_(3M) electrode used as a reference electrode, and a platinum electrode used as a counter electrode. Electrochemical experiments were controlled by using Nova version 1.5 software. Cyclic voltammetry was carried out at a scan rate of 100 mV/s. For the detection of SDZ in 0.1 M H₂SO₄ solution, the parameters for DPV (differential pulse voltammetry) were: increment—5 mV; amplitude—50 mV; sample period—100 ms; pulse time—10 ms.