Table 1.
Comparison of current NIR-IIb fluorescence/luminescence probes
| Required in vivo imaging exposure time (ms) | In vivo imaging frame rates (fps) | Excitation power (mW/cm2) | Constituent elements | Excretion | Emission life-time (μs)c | |
|---|---|---|---|---|---|---|
| PbS QDs9 | 2–5 | 30–60 | 60–70 | Pba, Cda, S | ~ 76% within 28 days | 46 |
| InAs QDs11 | 5000 | 0.2 | 60 | In, Asa, Cda, Se, S | --b | ~ 0.12 |
| CNTs8, 10 | 200 | 4.6 | 150 | C | Un-excretable | --b |
| β-ErNPs7, 43 | 50–1000 | 3 | 100–140 | Na, F, Yb, Y, Er | --b | --b |
| Ce-doped β-ErNPs34 | 20 | 25 | 150 | Na, F, Yb, Y, Er, Ce | --b | --b |
| α-ErNPs (this work) | 1.11–23.3 | 30–90 | 15–100 | Na, F, Yb, Y, Er, Ce, Zn | ~ 90% within 14 days | 4300 |
a
Class I toxic metals defined by United States Pharmacopeia (USP).
b
No data provided.
c
Long emission lifetime can be utilized for multiplexed imaging.