Stimulated-emission depletion (STED) microscopy has profoundly extended our horizons to the subcellular level^1,2,3. However, it remains challenging to perform hours-long, autofluorescence-free super-resolution imaging in near-infrared (NIR) optical windows under facile continuous-wave laser depletion at low power^4,5. Here we report downshifting lanthanide nanoparticles that enable background-suppressed STED imaging in all-NIR spectral bands (λ_excitation = 808 nm, λ_depletion = 1,064 nm and λ_emission = 850–900 nm), with a lateral resolution of below 20 nm and zero photobleaching. With a quasi-four-level configuration and long-lived (τ > 100 μs) metastable states, these nanoparticles support near-unity (98.8%) luminescence suppression under 19 kW cm⁻² saturation intensity. The all-NIR regime enables high-contrast deep-tissue (~50 μm) imaging with approximately 70 nm spatial resolution. These lanthanide nanoprobes promise to expand the application realm of STED microscopy and pave the way towards high-resolution time-lapse investigations of cellular processes at superior spatial and temporal dimensions.

受激发射耗尽 (STED) 显微镜已深刻地将我们的视野扩展到亚细胞水平^1,2,3。^{然而，在低功率4,5}的轻松连续波激光耗尽下，在近红外 (NIR) 光学窗口中执行长达数小时、无自体荧光的超分辨率成像仍然具有挑战性。在这里，我们报告了降档镧系元素纳米粒子，可以在全近红外光谱带（λ_激发 = 808 nm，λ_耗尽 = 1,064 nm 和λ_发射 = 850–900 nm）中实现背景抑制 STED 成像，横向分辨率低于 20 nm 和零光漂白。具有准四级配置和长寿命（τ^{> 100 μs) 亚稳态，这些纳米粒子在 19 kW cm -2}饱和强度 下支持近乎一致 (98.8%) 的发光抑制。全 NIR 方案可实现具有大约 70 nm 空间分辨率的高对比度深层组织（~50 μm）成像。这些镧系元素纳米探针有望扩大 STED 显微镜的应用领域，并为在更高的空间和时间维度上对细胞过程进行高分辨率延时研究铺平道路。