The UV-Vis-NIR absorption spectra were performed using a PerkinElmer Lambda 365 spectrophotometer. 1H and 13C spectra were recorded at room temperature on a Unity-400 NMR spectrometer using CDCl3 as solvent and tetramethylsilane (TMS) as a reference. Photoluminescence (PL) measurement was performed using a Horiba FluoroMax-4 Spectrofluorometer. The size distribution and average size of the DIPT-ICF NPs were performed by DLS using a Zeta-plus potential analyzer. TEM images were captured by a FEI Tecnai F20 microscope (accelerating voltage of 200 kV). Density functional theory (DFT) calculations were carried out by the B3LYP/6G(d), Gaussian 09 package. All the NIR-II images were captured through Full spectrum in vivo fluorescence imaging system (Suzhou NIR-Optics Technology Co., Ltd.).