Copper nanopowder

All chemicals used in this investigation were of analytical reagent grade. Water was purified by a Milli-Q Ultra Pure Water System (Millipore, Bedford, MA, USA). Diazepam, flunitrazepam, and lorazepam were purchased from Sigma-Aldrich (Madrid, Spain). All the samples were diluted in Britton-Robinson Buffer, pH 10 (0.04 M H₃BO₃, 0.04 M H₃PO₄, 0.04 M CH₃COOH, and 0.1 M NaOH). Modifiers employed in the preparation of electrodes were purchased from Sigma-Aldrich: platinum nanopowder, 50 nm particle size (Ref. 6845453); copper (II) oxide, 50 nm particle size (Ref. 544868); copper nanopowder, 40–60 nm particle size (Ref. 774111); and tungsten (VI) oxide, 100 nm particle size (Ref. 550086).

Polycaprolactone polymer (PCL, average M_n ≈ 80 000, ρ = 1.15 g cm^–3, T_m = 61 °C) was
used for the fabrication of the electrospun fibers. Chlorpyrifos (PESTANAL,
analytical standard), and Copper nanopowder (Cu, average particle
size 25 nm) were purchased from Sigma-Aldrich, the absence of oxidized
Cu due to the storage was confirmed by Raman spectroscopy (see Supporting
Information, Figure S3). Chloroform, methanol,
and ethanol were purchased from Scharlab. Deionized water was obtained
from a RiOs-DI 3 Water Purification device.

Reagents: poly(ethyleneimine), branched, Mn ~ 60,000, Mw 750,000, analytical standard, 50% (w/v) in H₂O (Sigma-Aldrich, Munchen, Germany); poly(sodium 4-styrene sulfonate), Mw ~ 70,000, (Sigma-Aldrich, Munchen, Germany); propidium iodide (Sigma-Aldrich), trypsin EDTA solution C (0.5%), EDTA 0.2% (10×) (Biological Industries, Kibbutz Beit HaEmek, Israel), phosphate-buffered saline (PBS) (Biomed Lublin, Lublin, Poland), MilliQ water; silver nanoparticles, 100 ppm, of 10 nm size, stabilized with sodium citrate, in 0.01% Tween 20 (University Technology Transfer Centre of the University of Warsaw (UTTC UW): Bell Synthesis, Poland, EU); golden nanoparticles, 100 ppm, of 10 nm size, stabilized with sodium citrate, in 0.01% Tween 20 (UTTC UW: Bell Synthesis, Warsaw, Poland); copper nanopowder 25 nm particle size (Merck/Sigma-Aldrich); iron (II) chloride tetrahydrate (Sigma Aldrich, St. Louis, MO, USA); iron (III) chloride hexahydrate (Sigma Aldrich, St. Louis, MO, USA).
Media: Ham’s F12 Medium/Dulbecco’s Modified Eagle’s Medium (F12/DMEM) (Gibco, Thermo Fisher Scientific, Waltham, MA, USA); Fetal Bovine Serum (FBS) (Sigma).
Culture medium: F12-K medium (Kaighn’s Modification of Ham’s F-12 Medium) supplemented with 10% FBS (Gibco, Thermo Fisher Scientific, Waltham, MA, USA). Cells: Human adenocarcinoma A549 cell line from human lung.