Sulfuric acid

Acetonitrile (#271004,
99.8%, MW = 41.08 g/mol), acrylamide (#A9909, 99%, MW = 71.08 g/mol),
azobis(2-methylpropionitrile) (#441090, 98%, MW = 164.31 g/mol), glyphosate
(#45521, 98%, MW = 169.07 g/mol), N,N′-methylenebis(acrylamide) (#146072, 99%, MW = 154.17 g/mol),
toluene (#244511, 99.8%, MW = 92.14 g/mol), and trimethoxy(7-octen-1-yl)silane
(#452815, 80%, MW = 232.39 g/mol) were purchased from Merck (Poznan,
Poland). Ethanol (#BA6480111, 99.8%, MW = 46.08 g/mol) and isopropanol
(#BA1500111, 99.7%, MW = 60.11 g/mol) were from POCh (Warsaw, Poland).
Hydrogen peroxide (#118851934, analytical grade, MW = 34.01 g/mol)
and sulfuric acid (#115750013, 98%, MW = 98.08 g/mol) were procured
from Chempur (Piekary Slaskie, Poland). Acetone (#50-8123, 99.8%,
MW = 58.08 g/mol) was obtained from Linegal Chemicals (Warsaw, Poland).
Fused silica slides were provided by TedPella (GE124, #26009; Redding,
CA), while commercial fused silica microcapillaries were purchased
from Postnova (#FSS-Z-200280; Landsberg, Germany).

Chemical substances used for synthesis of aniline nanofibers, aniline monomer, hydrochloric acid (HCl), ammonium persulfate (APS) and tetrahydrofuran (THF), were purchased from Chempur (Piekary Slaskie, Poland). Polyaniline nanofibers doped with Cl^- ion-synthesized following the procedure described in the publication [39 (link)]. Substances necessary for preparation of the membrane mixture were purchased from Sigma-Aldrich (Saint Louis, MO, USA) (chloride ionophore III-selectophore, tridodecylmethylammonium chloride (TDMACl) and high-molecular-weight poly(vinyl) chloride) (PVC)) and Fluka (Buchs, Switzerland) (bis(2-ethylhexyl) sebacate (DOS)). Sulfuric acid and sodium hydroxide used to measure the dependence of the electrode potential on changes in pH were obtained from Chempur, while the salts of iron(II) (Na₄Fe(CN)₆ × 10H₂O) and iron(III) (K₃Fe(CN)₆) were used to prepare the solutions differing in redox potential, respectively, from Alfa Aesar (Haverhill, MA, USA) and PPH (Polish Chemical Reagents, Gliwice, Poland). Other substances, such as inorganic salts, used to prepare the solution of the main ion (NaCl) and sodium salts of selected interfering anions (NaH₂PO₄, CH₃COONa, Na₂CO₃, NaNO₃, NaNO₂, Na₂SO₄, NaF, NaBr) were purchased from Fluka. Salts of the highest purity available (pure pro analysis) and freshly deionized water were used to prepare all solutions.

Polished silicon wafers were purchased from ON Semiconductor (Rožnov pod Radhoštěm, Czech Republic). 3-Aminopropyl-trimethoxysilane (APTES), 2-bromoisobutyryl bromide (BriBBr, 98%), ethyl 2-bromo-2-methylpropionate (EBIB, 98%), triethylamine (TEA, >99.5%) tetrahydrofuran (THF, >99.9%), acetone (DMK, >99.9%), tetrabutylammonium perchlorate (TBAP, >98%), and sodium bromide (NaBr, >99%) were purchased from Sigma Aldrich (Saint Louis, MO, USA). Dichloromethane (DCM, >99.5%), toluene (>99.5%), methanol (MeOH, >99.8), ethanol (EtOH, 99.9%), hydrogen peroxide (H₂O₂, 30%), and sulfuric acid (>95%) were purchased from Chempur (Piekary Śląskie, Poland). N,N-Dimethylformamide (DMF, 99.9%) was purchased from Acros (Fair Lawn, NJ, USA). These reagents were used without further purification. Tris(2-pyridylmethyl)amine (TMPA) was synthesized according to a published procedure [61 (link)]. A Cu^IIBr₂/TPMA stock solution was prepared according to reference [62 (link)]. 2-Hydroxyethyl acrylate (HEA; 96%; Aldrich) and tert-butyl acrylate (tBA; >99%; Aldrich) were passed through a column filled with basic alumina prior to use to remove monomethyl ether hydroquinone as an inhibitor. Al wire was purchased from Alfa Aesar (Tewksbury, MA, USA). LDPE cable ties were purchased from LUX-Tools (Wermelskirchen, Germany).