A novel system for Fe3+ ion detection based on fluorescence resonance energy transfer

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 mu M for C120 and 20 mu M for FL. The effects of various metal ions such as Li+, Na+, Ag+, Zn2+, Pb2+, Mn2+, Hg2+, Cu2+, Cd2+, Fe3+, Cr3+ and Al3+ on the energy transfer between the C120 and FL were explored. It was observed that the presence of Fe3+ 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 Fe3+ ions. The detection limit and binding constant of Fe3+ were determined as 2.54 mu M and 4.33 x 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 Fe3+. (C) 2015 Elsevier B.V. All rights reserved.