Case (iii) LRET but sensor response is based on the UCNP emission
18. Xylenol orange
β-NaYF 4 :Yb,Tm@SiO
2
50
4–8
I
450 (Tm)/I
646 (Tm)
2015 [65]
19. Fluorescein isothiocyanate
β-NaYF 4 :Yb,Tm@PEI
22
3–7
I
475 (Tm)/I
645 (Tm)
2016 [66]
20. Dopamine
β-NaYF 4 :Yb,Tm@NaYbF
4 @SiO
2
50
5–8
I
450 (Tm)
2019 [51]
21. Fluorescein
β-NaYF 4 :Yb,Tm @CB@Y
24
 29
3.2–4.8
I
825 (Tm)/I
475 (Tm)
2020 [54]
Cases (ii) and (iii)
22. Calcium red
Alizarin red S
β-NaYF 4 :Yb,Er@β-NaYF
4
@PEI/PMA
25–30
4.6–5.2
4.4–6.4
I
540 (Er)/I
650 (Er)
2019 [53]
PEG
polyethylene glycol, PEI
polyethylenimine, BSA
bovine serum albumin, PAA
poly(acrylic acid), GM
glutathione and mercaptopropionic acid, PMA
poly
(isobutylene-alt-maleic anhydride), CB
cucurbit[7]uril
Functional Nanohybrids Based on Dyes and Upconversion Nanoparticles
383