Pananalytic x pert pro

Absorption spectra of prepared samples were recorded at the wavelength of 300–900 nm with a resolution of 0.5 nm (Shimadzu UV-1800 spectrometer, Reinach BL, Switzerland). Crystallinity and phase-purity were analyzed at powder X-ray diffraction (PXRD) (PanAnalytic X’Pert Pro, Malvern Instruments, UK) with Cu-Kα radiation (λ=0.15405 nm, at 45 kV and 40 mA). Structural characterization was further assessed through FETEM (JEM-2100F, JEOL, Inc., Tokyo, Japan). Elemental analysis was done by energy dispersive X-ray spectroscopy (EDS). Mapping of elemental distribution of SnO₂-ZnO/rGO NCs was further done through FESEM (JSM-7600F, JEOL, Inc.). Hydrodynamic size and zeta potential in distilled water and culture medium were determined by DLS (ZetaSizer, Nano-HT, Malvern Instruments).

The purity of phase
and crystalline nature of prepared pure and Zn-doped (1 and 3%) Bi₂O₃ NPs were assessed by X-ray diffraction (XRD)
(PanAnalytic X’Pert Pro, Malvern Instruments, UK) with Cu-Kα
radiation (λ = 0.15405 nm, at 45 kV and 40 mA). Structural characterization
was carried out by FETEM (JEM-2100F, JEOL, Inc., Tokyo, Japan). In
brief, stock suspension of NPs (1 mg/mL in deionized water) further
diluted into an appropriate working suspension (50 μg/mL in
deionized water). This suspension was sonicated for 15 min at 40 W
in a water bath sonicator (Cole-Parmer, Vernon Hills, IL, USA). Then,
a drop of working suspension of NPs was poured onto TEM grid and air-dried,
and the TEM measurements were carried out. Elemental composition assessed
by EDS. Surface morphology and elemental mapping were assessed by
FESEM (JSM-7600F, JEOL, Inc.). The photoluminescence spectra were
observed using a fluorescent spectrophotometer (Hitachi F-4600).
Aqueous behavior of prepared NPs in deionized water and complete
culture medium (DMEM + FBS) was carried out by dynamic light scattering
(DLS) (ZetaSizer, Nano-HT, Malvern Instruments). In brief, NPs were
suspended in deionized water and culture medium at a concentration
of 400 μg/mL and incubated for 24 h at 37 °C. Then, suspensions
were sonicated for 15 min at 40 W in a water bath sonicator (Cole-Parmer)
and the DLS measurements were carried out.

The crystal structure
and crystalline phase of prepared samples were investigated by recording
XRD patterns (PanAnalytic X’Pert Pro, Malvern Instruments,
UK) with Cu Kα radiation (=0.15405 nm, at 45 kV and 40 mA).
Scanning electron microscopy (SEM) was employed to study the morphologies
of the synthesized samples. The chemical elements and states of the
prepared samples were examined by EDX and XPS, respectively. Raman
spectra were recorded using the WITec alpha 300RA Raman Confocal Microscope.
A Fourier transform infrared (FTIR) spectrometer (PerkinElmer Paragon
500) recorded the group function of the obtained samples at the wavenumber
range of 500–4000 cm^–1. A UV–visible
spectrophotometer (Hitachi U-2600) and a fluorescence spectrometer
(Hitachi F-4600) were used to analyze the optical properties of the
prepared samples.