A sensing microfibre mat produced by electrospinning for the turn-on luminescence determination of Hg2+ in water samples

A novel turn-on fluorescent microfibre mat with high selectivity towards Hg2+ has been prepared for determining and quantifying Hg2+ in water samples. It is based on the use of electrospinning for encapsulating a spirocyclic Rhodamine 6G phenyl-thiosemicarbazide derivative (called FC1) into polymeric microfibres and the well-known spirolactam (non fluorescent) to ring opened amine (fluorescent) equilibrium of Rhodamine derivatives as recognition mechanism. The fluorescence intensity was proportional to Hg2+ concentration in a linear range from 0.4 to 4.0 μM with a detection limit (S/N = 3) of 0.1 μM.