Multi-step FRET occurred from Pyrene (Py) to Rhodamine B (RhB) via Acriflavine (Acf).
Acf acts as an antenna to receive energy from Py and to transfer energy to RhB.
Multi-step FRET can be used to study molecular level interaction beyond 1–10 nm.
Incorporation of nanoclay laponite enhances the energy transfer efficiency.