Cu kα radiation

Grazing incidence X-ray diffraction (GIXRD) was carried out on an Empyrean Diffractometer using Cu Kα radiation (λ = 1.541874Ǻ) (PANalytical, Almelo, The Netherlands), equipped with a Hybrid monochromator 2 × Ge (2 2 0) for Cu and parallel plate collimator on PIXcel3D detector. The scan was made range of 5°–80° with an incidence angle of 0.5°, a step size of 0.04° and counting time per step on 2θ axis in the of 3 s.
IR mappings were recorded on an iN10 MX FT-IR Microscope (Nicolet, Walthman, MA, USA) with MCT liquid nitrogen cooled detector in the 4000–700 cm⁻¹ range. Spectral collection was made in reflection mode at 4 cm⁻¹ resolution. For each spectrum, 32 scans were co-added and converted to absorbance using OmincPicta software (Thermo Scientific, Walthman, MA, USA). Approximately 250 spectra were analyzed for each sample. One absorption peak known as being characteristics for the prepared material was selected as spectral marker.
SEM analysis was performed on a FEI electron microscope (FEI Hillsboro, OR, USA), using secondary electron beams with energies of 30 keV on samples covered with a thin gold layer.

The XRD spectra were obtained by θ from 5 to 40° with Cu Kα radiation (Panalytical Empyrean, Almelo, Netherlands). The UV-Vis spectra of the samples were measured with a UV-Vis spectrometer in the range of Libra (Biochrom, Berlin, Germany). Fourier transform infrared (FTIR) spectra were obtained on a Frontier FTIR spectrometer (Perkin Elmer, Waltham, MA, USA) in ATR mode using a ZnSe crystal from 400 to 4000 cm⁻¹. The SEM morphology was observed by scanning electron microscopy (SEM) (JCM 6000–Jeol microscope, Tokyo, Japan) at an accelerated voltage of 15 kV. The samples were then sputtered with a thin layer of gold.

Morphology and structure of the products Fe₃O₄, Fe₃O₄@SiO₂, Fe₃O₄@SiO₂-NH₂, Fe₃O₄@SiO₂-NH₂-RAFT, Lys-PMNP and Lys-PMNP-TEMED were observed in a FEI Tecnai G² 20 X-Twin transmission electron microscope (TEM) (FEI, Hillsboro, OR, USA) using 200 kV accelerating voltage and a Hitachi S-4800 scanning electron microscope (SEM) (Hitachi High-Tech Co., Ltd., Fukuoka, Japan) using 30 kV accelerating voltage. Infrared spectra were taken by a Spectrum Two Fourier-transform infrared (FTIR) spectrometer (Perkin Elmer) (Liantrisant, UK). Thermogravimetric (TG) analysis was carried out using a Q600 thermal analyzer (TA Instruments Inc., New Castle, DE, USA) in air. X-ray diffraction (XRD) patterns were recorded by an X’pert Pro MPD X-ray diffractometer using CuKα radiation (PANalytical, Almelo, The Netherlands). The zeta potential of the NPs in aqueous solution was measured with a Zetasizer Nano-ZS instrument (Malvern Instruments, Malvern, UK). To quantify the amino groups on the particles during synthesis, a BioTek instrument (Winooski, VT, USA) was used.