Triple‐channel NIR‐II fluorescence imaging of LNs, blood vessels, and ureters on rats. a) The differences of absorption and PL spectra among the three kinds of NPs (IDSe‐IC2F NPs, TQ‐BPN NPs, and PEG‐CSQDs). b) NIR‐II fluorescence images of these kinds of NPs by using different excitation light sources (623 nm LED and 793 nm laser) and different optical filters (1000 and 1500 nm LP). c) i) NIR‐II fluorescence imaging of major blood vessels labeled with TQ‐BPN NPs (before injection of IDSe‐IC2F NPs, 623 nm LED excitation, and 1100 nm LP); ii) LNs were labeled with IDSe‐IC2F NPs and imaged (793 nm laser excitation, 1100 nm LP); iii) retrograde ureteropyelography via PEG‐CSQDs based NIR‐II fluorescence imaging (793 nm laser excitation, 1500 nm LP); iv) merged image of (i)–(iii).