Figure 3

SERS imaging of a HeLa cell treated with MBA-coated AuNPs (A), CV-coated AuNPs (B) and CVa-coated AuNPs (C).

(A1–C1) Bright-field images and (A2-C2) SERS images corresponding to the detected HeLa cell. (A3–C3) SERS spectra obtained from different positions within the cell via point by point detection (1 μm × 1 μm) along the dotted line in (A1–C1) with an incident laser power of 3.0 mW and 1 s exposure time per spectrum. (A4–C4) The histogram displays the Raman intensity at 1078 cm⁻¹ (MBA-coated, A4), 1175 cm⁻¹ (CV-coated, B4) and 595 cm⁻¹ (CVa-coated, C4) obtained from the spectra in (A3–C3) along the dotted line in (A1–C1) (scale bar ≡ 4 μm).