2.2. Instrumentation
All fluorescence measurements were carried out on a Perkin-Elmer
LS 55 Luminescence Spectrometer (Waltham, USA). The emission spectra
were scanned from 200 to 800 nm. The excitation and emission slit
width were both set to 5 nm. Thermogravimetric analysis was performed
with a Seteram SETSYS thermal analyzer at a temperature
range of 25–950 °C at a heating rate of 10 °C min−1 under an argon atmosphere
with a gas flow rate of 20 mL min−1
. FT-IR spectra were recorded
on a Perkin-Elmer spectrum 100 FT-IR spectrometer (ATR)
(Perkin-Elmer Inc., USA). The magnetization curves of samples were
measured with a vibrating sample magnetometer (VSM, LakeShore-
7407, USA) at room temperature. SEM images were obtained using a
Zeiss LS-10 field emission SEM instrument equipped with an Inca Energy
350 X-Max (Oxford Instruments) spectrometer. Samples were
sputter-coated with a Au (60%) and Pd (40%) alloy using a Q150R (Quorum
Technologies) instrument. Images were obtained at 3 × 10−4 Pa
working pressure and 15 keV accelerating voltage using InLens detection
mode (2 mm working distance). The size and shape of the SPIONs
was determined by transmission electron microscopy (TEM, FEI
Company-Tecnai™ G2 Spirit/Biotwin).