Fig. 4: Summary of targeted super-resolution techniques based on upconversion inhibition saturation of lanthanide ion-doped UCNPs.

a Schematic of the energy level diagram of Pr³⁺-doped UCNPs for super-resolution ESA microscopy. Reproduced with permission from ref. ⁷⁷. Copyright 2011 American Physical Society⁷⁷. b Schematic of the sequence of laser pulses for super-resolution ESA microscopy imaging of Pr³⁺-doped UCNPs. Reproduced with permission from ref. ⁷⁷. Copyright 2011 American Physical Society⁷⁷. c Confocal and super-resolution ESA microscopy imaging of Pr³⁺-doped UCNPs. Reproduced with permission from ref. ⁷⁷. Copyright 2011 American Physical Society⁷⁷. d Schematic of the energy level diagram of lanthanide ion-doped UCNPs with high Tm³⁺ doping for UCL emission excitation and inhibition through STED. Reproduced with permission from ref. ⁷⁸ Copyright 2017 Springer Nature Limited⁷⁸. e Schematic of the super-resolution STED microscopy imaging system based on spatially overlapped Gaussian-shaped excitation and donut-shaped depletion laser beams and lanthanide ion-doped UCNPs with high Tm³⁺ doping. Reproduced with permission from ref. ⁷⁸. Copyright 2017 Springer Nature Limited⁷⁸. f Confocal and super-resolution STED microscopy imaging, and corresponding intensity profiles of lanthanide ion-doped UCNPs with high Tm³⁺ doping. Scale bars: 500 nm (main images) and 200 nm (insets). Reproduced with permission from ref. ⁷⁸. Copyright 2017 Springer Nature Limited⁷⁸. g Dual-color confocal and super-resolution STED microscopy imaging, and corresponding intensity profiles of lanthanide ion-doped UCNPs with high Tm³⁺ doping. Scale bar: 1 μm. Reproduced with permission from ref. ⁷⁹, CC BY 4.0. Copyright 2017 Springer Nature Limited⁷⁹. h Schematic of the SMED mechanism for UCL emission depletion through surface migration. Reproduced with permission from ref. ⁸⁰, CC BY 4.0. Copyright 2022 Springer Nature Limited⁸⁰. i Schematic of the energy level diagram of lanthanide ion-doped UCNPs with surface quenchers for super-resolution SMED microscopy. Reproduced with permission from ref. ⁸⁰, CC BY 4.0. Copyright 2022 Springer Nature Limited⁸⁰. j Confocal and super-resolution SMED microscopy imaging, and corresponding intensity profiles of lanthanide ion-doped UCNPs with surface quenchers. Reproduced with permission from ref. ⁸⁰, CC BY 4.0. Copyright 2022 Springer Nature Limited⁸⁰