Tris hydrochloride

Iron(iii) chloride hexahydrate (FeCl₃·6H₂O, 97%), iron(ii) chloride tetrahydrate (FeCl₂·4H₂O, 99%), sodium hydroxide (NaOH, 98%), citric acid (ca, 99.5%), tetraethyl orthosilicate (TEOS, 98%), ammonium hydroxide (NH₄OH, 28–30%), (3-aminopropyl)triethoxysilane (APTES, 98%), and acetic acid (CH₃CO₂H, 99.7%) were acquired from SigmaAldrich® for preparation and modification of the nanostructures. Double-stranded deoxyribonucleic acid (ds-DNA) sodium salt from salmon testes, tris hydrochloride (Tris–HCl, 99%), ethylenediaminetetraacetic acid (EDTA, 99%), sodium chloride (NaCl, 99.5%), and polyethylene glycol 8000 (PEG-8000) were also purchased from SigmaAldrich® for condensation of DNA onto the core–shell surface. Lead(ii) nitrate (Pb(NO₃)₂, 99.9%), sodium (meta)arsenite (NaAsO₂, 90%), and mercury chloride (HgCl₂, 99.5%) were obtained from SigmaAldrich® for the adsorption experiments. Ethanol absolute, reagent alcohol, and distilled water were used in all experiments.

Citric acid, sodium phosphate monobasic monohydrate, and sodium phosphate dibasic heptahydrate were purchased from Fisher Chemicals (Loughborough, U.K.). Glacial acetic acid was purchased from VWR (Lutterworth, U.K.). Sodium hydroxide pellets, sodium chloride, Tris‐hydrochloride, Tris‐base, sodium sulphate, sulphuric acid, hydrochloric acid, and glycine were purchased from Sigma‐Aldrich (Gillingham, U.K.).

Synthesis of DiLeu labels required purchasing the following isotopic reagents from ISOTEC Inc (Miamisburg, OH): leucines (ʟ-leucine and ʟ-leucine-1-¹³C, ¹⁵N), heavy Formaldehyde (CD₂O, 20% w/w), sodium cyanoborodeuteride (NaBD₃CN), ¹⁸O water (H₂¹⁸O), and deuterium water (D₂O). Formaldehyde (CH₂O, 37% w/w), sodium cyanoborohydride (NaBH₃CN), trifluoroacetic acid (TFA), iodoacetamide (IAA), hydrogen chloride gas (HCl), tris hydrochloride, reagent-grade formic acid (FA), N,N-dimethylformamide (DMF), triethylammonium bicarbonate (TEAB), 4-(4, 6-dimethyoxy-1, 3, 5-triazin-2-yl)-4-methylmorpholinium tetrafluoroborate (DMTMM), sodium azide (NaN₃) and N-methylmorpholine (NMM), and dithiothreitol (DTT) were purchased from Sigma-Aldrich (St. Louis, MO). Sequencing-grade trypsin was bought from Promega (Madison, WI). Urea, ACS grade methanol (MeOH), dichloromethane (DCM, CH₂Cl₂), acetonitrile (ACN, C₂H₃N), Optima LC-MS grade ACN, water, and FA were acquired from Fisher Scientific (Pittsburgh, PA). Hydroxylamine (H₃NO, 50%) was purchased from Alfa Aesar (Ward Hill, MA).

All reagents were of the highest quality available. Bovine serum albumin (fraction V), dithiothreitol (DTT), NAD⁺, l-glutamine, l-asparagine, l-malate, sodium 2-OG, potassium phosphate, hydroxylamine hydrochloride (stock solutions neutralized with NaOH before use), tris hydrochloride, glycine, sodium hydroxide, ferric chloride, lithium lactate, trichloroacetic acid, glycylglycine and protease inhibitor cocktail were obtained from Sigma Aldrich Chemical Company (St. Louis, MO, USA). Succinamic acid was obtained from Aldrich Chemical Company (Milwaukee, WI, USA). 2,4-Dinitrophenylhydrazine was obtained from Eastman Kodak (Rochester, NY, USA). Stock solutions of 2-OGM, in which the pH was adjusted to around 6.0 with NaOH, were prepared by the method of Krasnikov et al. [45 (link)].

Acetylthiocholine (AcSCh), acetylcholinesterase (AChE), butylated hydroxytoluene (BHT), dimethyl sulfoxide (DMSO), dichloromethane (DCM), donepezil, magnesium chloride hexahydrate, methanol (MeOH), phosphate-buffered saline (PBS), sodium sulfate anhydrous, tris hydrochloride (Tris-HCl), trolox, 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 2,2-diphenyl-1-picrylhydryl (DPPH), and 5,5′-dithiobis (2-nitrobenzoic acid) (DTNB) were purchased from Sigma-Aldrich (San Luis, MO, USA). Fluid thioglycollate medium, Mueller-Hinton II broth, Mueller-Himton broth, and Sabouraud dextrose broth were purchased from DIPCO (Quito, Ecuador). Helium was purchased from INDURA (Quito, Ecuador). The standard aliphatic hydrocarbons were purchased from ChemService (West Chester, PA, USA). All the chemicals were of analytical grade and used without further purification.