U 3100 spectrophotometer

X-ray diffraction (XRD) was conducted with a Rigaku D/max-TTR-III diffractometer utilizing Cu-Ka radiation (λ = 0.15405 nm). Transmission electron microscopy images were captured on an FEI Tecnai G²S-Twin with a field emission gun operating at 200 kV. A Hitachi U-3100 spectrophotometer was used to characterize the UV-visible spectra of the samples. The solution of the UCNPs@mSiO₂-Ce6 (1 mg/mL) was oscillated in the constant temperature water bath oscillator, and the ultraviolet absorption spectra at 650 nm was measured before and after centrifugation (2000 rpm, 5 mins) once a day to evaluate the stability of Ce6. Fourier transform infrared (FT-IR) spectroscopy spectra were got on a Perkin-Elmer 580BIR spectrophotometer utilizing the KBr pellet as the background. The fluorescence life curves of the samples were recorded and measured using the Tektronix MSO/DPO4000 oscilloscope. Upconversion emission spectra were tested on a R955 Hamamatsu photomultiplier tube, from 400 to 800 nm, the 808 nm laser diode module (K98D08M-30W, China) was used as the irradiation source. The images of confocal microscopy were recorded by a Leica TCS SP8. All the measurements were performed at room temperature.

The X-ray diffraction date were collected in a D8 Advanced diffractometer (Bruker) using CuKα radiation (λ = 0.154 nm). Transmission electron microscopy measurements were carried out on a FEI Tecnai G2 S-Twin with a field emission gun operating at 200 kV. Dynamic light scattering (DLS) and surface zeta potential measurements were performed on a Malvern instrument Zatasizer Nano. N₂ adsorption/desorption analysis was measured on a Micromeritics ASAP 2020M apparatus. The Brunauer-Emmett-Teller (BET) method was used to calculate the specific surface area of samples from the data between 0.05 and 0.35, and t-plot method was to calculate the pore volume. The UV-vis absorption spectra were obtained from U-3100 spectrophotometer (Hitachi). Fourier transform Infrared spectra (FT-IR) were obtained by a PerkinElmer 580BIR spectrophotometer using KBr pellets. The X-ray photoelectron spectra (XPS) were performed on an ECSALAB 250. The UC emission spectra were carried out from an F-7000 fluorescence spectrometer (Hitachi) using a 980 nm laser as the excitation source. The digital photos of up-converting luminescence were obtained from a Canon camera. CLSM images were acquired from a FV 1000 confocal laser scanning microscrope (Olympus). A flow cytometry was recorded on a FCM cytometer (BD Biosciences) using 488 nm as excitation wavelength.