a-c) Chemical structure of renally excreted NIR-II dyes (CH1055PEG,[88] IR-E1,[98] and IR-BGP6[100, 101]) with D-A-D or S-D-A-D-S structures. d) Injection of CH1055-PEG and HiPCO SWCNTs fluorophores in mouse showed disparate liver and bladder signals, respectively, indicating the typical behavior of renally excreted molecules (imaging details: 1200 nm LP, 100 ms). Reprinted with permission from Ref. [88].