Fig. 4

a Intravital long-term hindlimb vasculature NIR-II imaging (1250-nm band-pass filter, 500 ms, 808-nm excitation) at 120 s, 300 s, and 15 min after tail vein injection of the PTZ-TQ-AIE dots. b The vessel FWHM width based on the cross-sectional intensity profile measured along the yellow line in (a) (120 s) with the peak fitted to Gaussian functions (the black curve is the Gaussian fit to the profile). c Representative in vivo long-term NIR-II fluorescence images (808-nm excitation, 1250-nm band-pass filter, 500 ms, n = 3) of the orthotopic liver cancer at different time points after tail vein injection of the PTZ-TQ-AIE dots (0.2 mL, 0.5 mg/mL). The white circles indicate the tumor. d The pictures of liver and tumor. Scale bar: 200 μm. e Illustration of the NIR-II optical imaging-guided tumor resection. f The NIR-II and bioluminescence imaging in surgery. g The relative tumor growth curve and corresponding fluorescence intensity of the tumor-bearing mice. Data are shown as means (n = 3). h Photographs of dissected liver after treatments