A novel up-conversion fluorescence resonance energy transfer sensor for the high sensitivity detection of coumarin in cosmetics

摘要

Coumarin is widely used as spices in a variety of cosmetics. However, its concentration in cosmetics is strictly limited because it is a kind of suspected carcinogen. It is essential and highly desired to develop fast and convenient detection methods to detect trace amount of coumarin. This work presents a novel and simplified fluorescent sensor for the determination of coumarin based on the phenomenon of fluorescence resonance energy transfer (FRET). In this system, the NaYF4: Yb,Er (NaYF) behaves as energy donor, and the rhodamine 6 G (Rh6 G) behaves as energy receptor. The beta-cyclodextrin (CD) was modified on NaYF and was used to ensure the selectivity towards coumarin and to bring the donor and receptor into FRET proximity through specific host-guest interaction, which is different from the previously reported FRET models that either rely on pi-pi stacking interaction or rely on molecular recognition. This fluorescent sensor shows high sensitivity and selectivity toward coumarin, and the linear response range is 2.5-32.5 mu M with a limit of detection as low as 0.74 mu M.