Al foil

NMR spectra were measured on a Bruker Avance II Plus (Bruker Corporation, Billerica, MA, USA) spectrometer (700 MHz for ¹H-NMR and 176 MHz for ¹³C-NMR) in CDCl₃ solution. ¹H and ¹³C-NMR spectra were referenced according to the residual peak of the solvent based on literature data. Chemical shifts (d) were reported in ppm and coupling constants (J) were reported in Hz. ¹³C-NMR spectra were proton-decoupled. Flash chromatography was performed using a glass column packed with Baker silica gel (30–60 μm). For TLC, silica gel was used with a 254 nm indicator on Al foils (Sigma-Aldrich, St. Louis, MO, USA). All reagents and solvents were purchased and used as obtained from Sigma-Aldrich (Poznan, Poland). Melting points were obtained using a Büchi SMP-20 apparatus. Mass spectrometry analysis was performed on a Bruker microOTOF-QIII (Bruker Corporation, Billerica, MA, USA) equipped with electrospray ionization mode and a time-of-flight detector (TOF). IR spectra were measured on an FT-IR Alpha Bruker (ATR) instrument in cm⁻¹.

All the following chemicals were used without
further purification: sulfobetaine methacrylate (SBMA, 98%, Taiwan
Hopax Chemicals), 4,4′-Azobis(4-cyanovaleric acid) (ACVA, 98%,
Sigma-Aldrich), 4-cyanopentanoic acid dithiobenzoate (CPAD, 97%, Strem
Chemicals), dopamine hydrochloride (DA, 98%, Tokyo Chemical Industry),
ethanol (95%, ECHO), acetone (99%, ECHO), isopropyl alcohol (IPA,
95%, Uni-Onward), methanol (95%, Uni-Onward), deuterated water (D₂O, 99.9%, Sigma-Aldrich), 2,2,2-trifluoroethanol (TFE, 99.8%,
Acros Organics), oxalic acid (H₂C₂O₄, 97%, Showa), chromium(VI) oxide (CrO₃, 98%, Showa),
copper chloride (CuCl₂, 98% Showa), hydrochloric acid (HCl,
>37%, Honeywell Fluka), phosphoric acid (H₃PO₄, >85% J. T. Baker), and perchloric acid (HClO₄, 70%,
Showa). Deionized (DI) water was obtained by a pure water system (RODA)
with a resistivity of 18.25 MΩ·cm. A 0.1 M tris(hydroxymethyl)aminomethane
(Tris) buffer solution with pH = 8.1 was prepared by dissolving a
preset pHast Pack powder (PPB023, Sigma-Aldrich) in DI water to a
total volume of 500 mL. 0.2 mm-thick aluminum foil (Al foil, 99.997%),
1 mm-thick aluminum oxide (Al₂O₃), and 1 mm-thick
glass substrates were procured from Alfa Aesar, Cheng Yang Instrument
Corp., and FEA, respectively.