Figure 3
(a) Two-photon imaging of Human hepatocellular liver carcinoma cell line (HepG2) after treated with P-QD for 2 h, 800 nm femtosecond laseras excitation.
Left: P-QD; middle: Hoechst; right: overlay. Note that these images were acquired by spectral imaging coupled with image analysis using linear unmixing. Scale bar: 50 μm. (b) Schematic of the procedure used for TPM of P-QD in tissue phantom with different thickness. The depth of tissue phantom was varied by adding different amounts of Intralipid. (c) Imaging depth of P-QD in tissue phantom under 800 nm femtosecond laser excitation. For comparison, the corresponding pictures under one-photon excitation (OPE) are also shown. Scale bar: 100 μm. (d) The signal-to-background ratio (SBR) as a function of depth. SBR was defined as the ratio of (signalwith P-QD − signalwithout P-QD) to signalwithout P-QD.
