Fig. 2
Proof-of-concept. a SpeRe measurements on polystyrene-based fluorescent reflectophores with a nominal size of 4 μm. The measured diameters are 3.756 μm for “i”, 3.742 μm for “ii”, 3.693 μm for “iii”, and 3.684 μm for “iv”. Diameters (d) were quantified by finding the best-fit simulated spectrum (R2: 0.99 for “i”, 0.98 for “ii”, 0.98 for “iii”, and 0.98 for “iv”). The upper panel shows fluorescent images on the corresponding reflectophores. b, c Measurement precision. A single silica-based reflectophore with a nominal size of 4 μm was repeatedly measured through SpeRe. Precision in standard deviation was ±0.78 nm (n = 21 measurements). The shaded blue area in b indicates maximum deviation. The value in c is presented as mean ± standard deviation. d–f Validation of the reflectophore measurements using a scanning electron microscope (SEM). The SpeRe measurements on multiple reflectophores were compared with the SEM measurements (unpaired Student’s t-test; monodisperse beads: 10.061 ± 0.0531 μm and 10.078 ± 0.0905 μm for SEM (n = 167 beads) and SpeRe (n = 30 beads), respectively, p = 0.147; polydisperse beads: 2.440 ± 0.065 μm and 2.457 ± 0.087 μm for SEM (n = 151 beads) and SpeRe (n = 30 beads), respectively, p = 0.206; The values are presented as mean ± standard deviation). The error bars in f represent standard deviation. Source data are provided as a Source Data File
