Figure 5

Photostability of PLGA nanoparticles encapsulating DDA-GSH-AuNCs. (A) Photoluminescence spectra and (B) relative photoluminescence intensity calculated as the ration between intensity after 24 hours of incubation (F₂₄) to the initial intensity (F₀) in water, PBS or DMEM as labeled. C) Photostability of PLGA nanoparticles encapsulating DDA-GSH-AuNCs in DMEM upon kinetic scan (λ_ex = 365 nm, λ_em = 605 nm, integration time of 0.1 s, total scan time of 300 S, 150 W xenon lamp). D) Photostability of PLGA nanoparticles encapsulating DDA-GSH-AuNCs (yellow bars), Nile Red (red bars) or fluorescein (green bars) upon irradiation with (364 nm, 80 mW, 248 mW/cm⁻²), (568 nm, 30 mW, 93 mW/cm⁻²) or (488 nm, 30 mW, 93 mW/cm⁻²), respectively. In (C,D): F₀ and F_(t) are the initial photoluminescence intensity before irradiation and at each time point as labeled, respectively. Data in (B) and (D) are mean ± SD, n = 3 for each group. Statistical analysis in (D) was performed by 2-way ANOVA with the Bonferroni post-hoc test. In (D), significant difference of PLGA-Nile red or PLGA-Fluorescein in reference to PLGA-DDA-GSH-AuNCs is calculated using (alpha of 0.05) and indicated by: *p < 0.5; ***p < 0.001; ****p < 0.0001; ns: not significant (p > 0.05).