Biomedical Engineering Reference
In-Depth Information
Figure 7.49
Step 2: Capture of the targets.
However, if another fluorophore is placed next to this fluorophore, it quenches
the light emission by energy transfer (Figure 7.56).
Using the FRET principle, it is possible to set up the protocol for a displacement
reaction [33]. First, the surface of capture is functionalized with tripods formed by
an antibody and a fluorophore (Figure 7.57). Then analogs marked with “quencher”
fluorophores are immobilized on the tripods by chemical affinity (Figure 7.58). It
results in a quenching of the fluorescence of the tripods.
The target antigens in the buffer fluid then displace the analogs with their fluo-
rophores, and the fluorescence increases again (Figure 7.59).
The advantage of this type of reaction is that of a typical displacement reac-
tion, plus the fact that the functionalized surface of capture can be regenerated just
by reintroducing the analogs in the microchamber. The microsystem can thus be
reused.
Figure 7.50
Step 3: Marking the targets with fluorophores.
