A novel system for Fe~(3+) ion detection based on fluorescence resonance energy transfer

摘要

A new sensor system was developed for metal-ion sensing based on fluorescence resonance energy transfer (FRET). FRET process was carried out between coumarin (C120) as the energy donor and fluorescein (FL) as the energy acceptor. The concentration most suitable for FRET efficiency was determined to be 0.2 μM for C120 and 20 μM for FL. The effects of various metal ions such as Li~+, Na~+, Ag~+, Zn~(2+), Pb~(2+), Mn~(2+), Hg~(2+), Cu~(2+), Cd~(2+), Fe~(3+) Cr~(3+) and Al~(3+) on the energy transfer between the C120 and FL were explored. It was observed that the presence of Fe~(3+) ions inhibited the energy transfer between the two molecules while the other metal ions did not affect. This observation shows that the C120-FL system could be selectively detected for Fe~(3+) ions. The detection limit and binding constant of Fe~(3+) were determined as 2.54 μM and 4.33 × 10~4 M~(-1), respectively. The C120-FL system has a good potential for a sensor application in analytical systems due to its high selectivity for Fe~(3+).