Fig. 2. Single-particle brightness analysis. (A) Simplified analysis workflow that includes: detection of local maxima, defining and measuring the intensity at regions of interest around maxima (raw signal: Iraw) and around central regions (background: Ibkg). The signal is then obtained by subtraction of the background from the raw signal. (B,C) Example of single-particle imaging by wide-field microscopy (B) and intensity analysis (C) for 20 nm DNA-modified dye-loaded polymeric NPs (organic NPs) vs. reference particles QD-605. In case of QD-605, the source irradiance was increased 65-fold to achieve comparable intensity with organic NPs. Other experimental settings were identical. Excitation wavelength was 550 nm. Panels B and C reproduced with permission from ref. 36. Copyright American Chemical Society.
