N n methylenebis

All chemicals listed here were used without
further processing, unless stated otherwise. APTES, MPTMS, 4-MBA,
HAuCl₄·3H₂O, iodine, potassium iodine,
and anhydrous toluene (99.8%) were purchased from Sigma-Aldrich. Acetone
(99%), calcium chloride, ethanol (96%), isopropanol (IPA) (≥98%),
absolute ethanol (99.96%), and hydrofluoric acid (40%) were acquired
from VWR. Hydrogen peroxide (30%) and tri-sodium citrate dihydrate
were obtained from Merck. Sulfuric acid (95–97%) was supplied
by Supelco. The MilliQ water used was double deionized using a MilliQ
system with a resistivity of 18 MΩ. N-doped Si wafers (<100>,
resistivity 1–30 Ω cm) were obtained from Si Materials,
Germany. For the synthesis of SiO₂@PNiPAm core–shell
particles used as a colloidal template, N,N′-methylenebis(acrylamide)
(99%), ammonium persulfate (98%), ethanol (99.9%), hexane (≥99%),
tetraethyl orthosilicate (98%), ammonium hydroxide solution (28–30%
NH₃ basis), (3(trimethoxysilyl)propyl methacrylate) (98%),
fluorescein isothiocyanate isomer I (>90%), and (3-aminopropyl)triethoxysilane
(>98%) were purchased from Sigma-Aldrich and used as received. N-Isopropylacrylamide (97%) was obtained from Sigma-Aldrich
as well but purified before usage by recrystallization from hexane
(95%, Sigma-Aldrich).^{70 (link)}

Adipic acid dihydrazide (ADH), succinic acid dihydrazide (SDH), malonic acid dihydrazide (MDH), N,N′-methylenebis (acrylamide), Span 60^®, CuCl₂ anhydrous, CdCl₂ were purchased from Sigma-Aldrich (Boston, MA, USA), Toluene was purchased from Junsei (Tokyo, Japan). All reactants were used without further purification. Optical microscopy (OM) images were obtained on a Nikon Eclipse (ME600) (Tokyo, Japan) and field emission scanning electron microscopy (FE-SEM) images were obtained from Hitachi SU 8230 (Tokyo, Japan). Energy-dispersive X-ray analysis (EDX) was performed on a Hitachi SU 8230 (Tokyo, Japan). Metal ion concentration was measured by an inductively coupled plasma optical emission spectrometer (Agilent ICP-OES 5110, Santa Clara, CA, USA). Fourier transform attenuated total reflectance infrared spectroscopy (FT ATR-IR) spectra were obtained from a Nicolet iS50 (Thermo Scientific, Hampton, NH, USA).