Optima camera

Dry ZGSO:0.5%Cr³⁺ NPs were weighted and dispersed into DI water filling 2 mL Eppendorf, (weighing, according to the targeted concentration, from 0.2 mg/mL to 2 mg/mL), via ultrasonic dispersion. ZGSO:0.5%Cr³⁺ NPs in suspension (series of concentration from 0.2 to 2 mg/mL) are transferred into a 96-well plate (0.3 mL for each suspension hole), and irradiated under a UV lamp for 2 min. The excited suspension was then observed using an Optima camera (Biospace Lab, Nesles-la-Vallée, France) for 5 min of acquisition in bioluminescence mode. After collection, M3-vision software was employed for data treatment.

Dynamic light scattering (DLS) and zeta potential measurements were performed on a Malvern Zetasizer-Nano instrument equipped with a 4 mW He-Ne laser (633 nm). DLS measurements were recorded by diluting colloidal aqueous suspensions of ZGO at a concentration of 0.1 mg/mL in water. Colloidal stability tests were performed at a NP concentration of 2 mg/ml. Zeta potential measurements were performed in 20 mM NaCl solution. Transmission electron microscopy (TEM) was performed at 80 kV on JEOL JEM-100S using 5 μL of suspension dropped for 1 min. Thermogravimetric analysis (TGA) was performed using a TGA/DSC 1 from Mettler-Toledo (Greifensee, Switzerland) sensitive to 1 μg and calibrated beforehand with internal standard weights. Samples of approximately 2 mg were analyzed in alumina pans with a central hole of 1 mm diameter. All the experiments were performed at a 5 K.min⁻¹ heating rate and under a dry airflow of 70 mL.min⁻¹. Infrared spectra were recorded on an Affinity-1 (Shimadzu). Persistent luminescence decays were performed on an Optima camera (Biospace Lab, France). Acquisitions of the luminescence of nanoparticles were recorded for 5 min after a 2-min excitation under UV light (365 nm) or a LED lamp (5,000 ml) with a 515 nm filter.

Luc level in the tumor was monitored by optical imaging 20 min after injection intraperitoneally (i.p.) of 2 mg luciferin substrate. Bioluminescence was recorded for 10 min with the Optima camera (Biospace Lab). The quantification was performed over a region of interest (ROI) applied to the tumors using M3 vision software and the results were presented as the total bioluminescence signal in the chosen ROI normalized with the background signal in the same area [bioluminescence imaging (BLI)/bg].