Notably, comparedwith visible (400–680 nm) and rst near-infrared region (NIR-I,700–900 nm), uorescence imaging in the second near-infraredwavelength region (NIR-II, 1000–1700 nm) shows salientadvantages of deep tissue penetration with high signal-to-background ratio (SBR), owing to the decreased scattering ofphotons at longer wavelengths