98%) is purified in glacial acetic acid by continuous stirring until
the suspension solution is pale white. After that, the acetic acid
is removed, followed by multiple washing cycles with ethanol. Next,
the resulting powder is dried in a vacuum oven (room temperature,
overnight). 3-Sulfopropyl methacrylate potassium salt (SPMAK, 98%),
(3-aminopropyl)triethoxysilane (APTES, 98%), α-bromoisobutyryl
bromide (BiBB, 98%), 2,2′-bipyridyl (≥98%), triethylamine
(TEA, ≥ 98%), and ethyl α-bromoisobutyrate (EBiB, ≥
98%) are purchased from Merck and used as received. Methanol (ACS
reagent) and toluene (ACS reagent) are purchased from Biosolve and
used as received. MilliQ water purified from a MilliQ Advantage A10
purification system (Millipore, Billerica, MA, USA) is used.