Fig. 4: Raman scattering cross-section of the SICTERS-based small-molecule nanoprobes compared to the SERS-based Au nanoprobes.
From: Self-stacked small molecules for ultrasensitive, substrate-free Raman imaging in vivo
a–c, Schematic structures and representative transmission electron micrographs (TEM) of the SICTERS-based BBT NPs (a), the SERS-based Au NPs (NBT@Au NPs) (b) and the SERS-based Au GERTs (NBT@Au GERTs) (c) of 69.1 nm, 68.3 nm and 70.6 nm in average diameters, respectively. Scale bars, 100 nm. The reporter molecule 4-NBT was incorporated into Au NPs or Au GERTs. Image shown is representative of n = 3 independent replicates of experiments with similar results (a–c). d, The Raman scattering cross-section for 4-NBT or BBT in different nanoprobes. The cross-section values per molecule were calculated by measuring the Raman peak at 1,340 cm−1 excited at 532 nm for 4-NBT or 4-NBT NPs; the Raman peak at 1,340 cm−1 excited at 785 nm for NBT@Au NPs or NBT@Au GERTs; and the Raman peak at 894 cm−1 excited at 830 nm for BBT NPs, while using the methanol C-O stretch at 1,020 cm−1 as the internal reference. n = 3–5 independent samples (d). Data are presented as the mean ± standard deviation (s.d.) (d).
