Diffuse optical localization imaging for noninvasive deep brain microangiography in the NIR-II window

Fluorescence microscopy is a powerful enabling tool for biological discovery, albeit its effective penetration depth and resolving capacity are limited due to intense light scattering in living tissues. The recently introduced short-wave infrared cameras contrast agents featuring fluorescence emission the second near-infrared (NIR-II) window have extended achievable about 2 mm. However, spatial resolution progressively deteriorates with photon diffusion. Here we introduce diffuse optical localization imaging (DOLI) enable super-resolution deep-tissue beyond limits imposed by method based on of flowing microdroplets encapsulating lead sulfide (PbS)-based quantum dots sequence epi-fluorescence images acquired NIR-II spectral window. Experiments performed tissue mimicking phantoms indicate that high-resolution detection fluorescent particles can be preserved over 4 mm range, while vivo microangiography murine cerebral vasculature accomplished through intact scalp skull. further enables retrieving information from planar image recordings exploiting localized spot size. DOLI operates resolution-depth regime previously inaccessible methods, thus massively enhancing applicability fluorescence-based techniques.