Fig. 2. Dual-channel and emission spectra measurements on CDPs and non-CDPs in suspensions with fs-pulsed NIR laser (810 nm, 80 MHz). (a) The Pearson's correlation coefficient between channel 1 and channel 2 for CDPs and non-CDPs calculated using coloc2 plugin in Fiji ImageJ. (b) The number of particles counted per ml in a biologically relevant concentration (20 μg ml⁻¹). The data are average ± SD (n = 8). (c) The emission spectra of the NP suspensions for both CDPs and non-CDPs employed in this study under fs-pulsed NIR laser illumination with an average laser power of 8 mW in focus. The background measured using ultrapure water was removed from the emission spectra of NPs.