Nicl2

Anhydrous commercial
reagents were stored in an inert atmosphere glovebox and utilized
as purchased: NiCl₂ (Alfa-Aesar, 99%), CoCl₂ (Alfa-Aesar, 99.7%), FeCl₃ (Alfa-Aesar, 98%), FeCl₂ (Aldrich Chemicals, 98%), MgB₂ (Alfa-Aesar, 99%),
Mg (Sigma-Aldrich, 99.5%, powder, −325 mesh), amorphous B (Alfa-Aesar,
95–97%, powder (APS < 1 μm)), and MgCl₂ (Cerac, 99.9%, powder, 100 mesh). HCl at 0.1 M (Fisher Scientific,
12.4 M diluted with DI H₂O) was used for the product washing.
ICP calibration standards were prepared by diluting Co (Alfa-Aesar,
999 ± 5 μg/mL), Ni (Alfa-Aesar, 1003 ± 6 μg/mL),
Fe (Alfa-Aesar, 1003 ± 6 μg/mL), and B (Inorganic Ventures,
9968 ± 52 μg/mL) in 5 vol % HNO₃ (from Sigma-Aldrich,
14 M diluted in 18 MΩ ultrapure water) and by dissolving Mg
powder (Sigma-Aldrich, 99.5%, −325 mesh powder) in 5 mL of
conc. HNO₃ and then diluting to 100 mL with water. Materials
used for electrochemical studies: synthetic graphite powder (Sigma-Aldrich,
<20 μm), paraffin wax (Sigma-Aldrich, mp ≥ 65 °C),
0.1 and 1.0 M KOH (Sigma-Aldrich, KOH pellets dissolved with 18 MΩ
ultrapure water), 0.5 M H₂SO₄ (Fisher Scientific,
95–98%, 18 M diluted with 18 MΩ ultrapure water), 10%
Pt on Vulcan XC-72 carbon (C1- 10 fuel cell grade, E-Tek), and RuO₂ (Alfa-Aesar, 99.9%).

All chemicals, benzoic acid (Aldrich, 99.5%), zirconyl chloride octahydrate (Aldrich, 98%), N,N-dimethylformamide (DMF) (Macron, 99.8%), hydrochloric acid (HCl, 36.5%–38.0%, Macron), acetone (Macron), NiCl₂ (Aldrich, 98%) and thiourea (Sigma, 99%) were used as received without further purification. Deionized water was used throughout the work. The chemicals used for the synthesis of the H₄TBAPy linkers were the same as those reported in our previous work25 (link).

H. pylori strains were tested for their sensitivity to nickel by the disc agar diffusion method. Therefore, 2.10⁶ CFU of each strain were prepared from liquid culture and were spread on plates containing Brucella broth, 1.5% bacto agar and 10% FCS. Sterile antibiotic assay discs (Whatman) were soaked in 4 μmol NiCl₂ (Sigma) and placed in the center of the plate. The data correspond to at least three independent experiments with two replicates per experiment. Growth inhibition diameters (zones of inhibition, ZOI) were measured after 5 days of culture. For tests of metal sensitivity during growth in liquid, H. pylori cells were inoculated at OD₆₀₀ 0.05 in 10 mL Brucella-Broth containing 10% FCS and increasing nickel concentrations (0, 5, 10, 30, 100 or 200 μM). Bacterial growth was monitored 17 hours later by measuring OD₆₀₀. The MIC₅₀ corresponds to the inhibitory nickel concentration that reduced growth by 50%.

Depending on different purposes of experiments, the ACSF with antagonists against NMDARs, AMPARs, GABA_ARs, and voltage-gated sodium channels was used for bath application of the following drugs: cyclopiazonic acid (30 μM, Sigma), Ry (10 μM; Tocris), thapsigargin (5 μM, Sigma), D600 (500 μM, Sigma), nimodipine (20 μM ; Sigma), SNX-486 (0.5 μM; Tocris and Alomone), ω-Agatoxin IVA (0.2 μM; Peptide institute INC., Japan), and NiCl₂ (75 μM; Sigma) as indicated in the respective “Results” section. Ca²⁺-free ACSF contained (in mM) 0.1 mM ethylene glycol-bis (β-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA; Sigma), 20 glucose, 4.5 KCl, 3 MgCl₂, 125 NaCl, 26 NaHCO₃, and 1.25 NaH₂PO4. Local drug application was performed by a glass pipette with the resistance of 8 MΩ, which was connected to a Picospritzer II (Parker instrumentation, general valve, USA). The mGluR1/5 agonist DHPG (500 μM; Abcam) was dissolved in ACSF and Ry receptor agonist caffeine (40 mM, Sigma) was diluted in caffeine ringer, which contained (in mM) 2 CaCl₂, 10 HEPES, 2.5 KCl, 1 MgCl₂.6H₂O, 120 NaCl, and 1.25 NaH₂PO₄. The pipette tip was placed at a distance of 15–20 μm from the cell soma.

Silver nitrate (AgNO₃), sodium borohydride (NaBH₄), mercaptoundecanoic acid (11MUA), NiCl₂, CoCl₂, ZnCl₂, CuCl₂, MnCl₂, CdCl₂, FeCl₂, HgCl₂, PbCl₂, and CrCl₃ were purchased from Sigma-Aldrich (St. Louis, MO, USA), and used without further purification. All the glassware was washed with boiling aqua regia before being used. All the solutions were prepared using ultrapure water (18.2 µS/cm).
Plots, fittings, and statistical analysis were performed by using MatLab R2020b (The MathWorks, Inc, Natick, MA, USA).

Ti₃AlC₂ (98%) was purchased from the Forsman Scientific Co., Ltd. (Beijing, China). Polyvinylidene fluoride (≥ 99.5%) was purchased from Micxy Chemical Co., Ltd. (Chengdu, China). Nickel form (110 mesh per inch) was purchased from Chuan Dong Chemical Co., Ltd. (Chongqing, China). Carbon black was purchased from Cabot Corporation (Boston, USA). Hydrochloric acid (HCl, ACS grade, 36-38%), lithium fluoride (LiF, ACS grade, ≥ 99%), n-methyl-2-pyrrolidone (ACS grade, ≥ 99.8%), NiCl₂ (ACS grade, ≥ 99%), Se powder (ACS grade, ≥ 99%), KOH (ACS grade, ≥ 99%), and EDTA-Na₂ (ACS grade, ≥ 99%) were purchased from Sigma-Aldrich. All chemical materials were used as received without further purification.