Spectral characterization of a newly synthesized fluorescent semicarbazone derivative and its usage as a selective fiber optic sensor for copper(II) Original Research Article

In this work photoluminescent properties of highly Cu2+ selective organic fluoroionophore, semicarbazone derivative; bis(naphtho[2,1-b]furan-2-yl)methanone semicarbazone (BNF) was investigated in different solvents (dichloromethane, tetrahydrofuran, toluene and ethanol) and in polymer matrices of polyvinylchloride (PVC) and ethyl cellulose (EC) by absorption and emission spectrometry. The BNF derivative displayed enhanced fluorescence emission quantum yield, Qf = 6.1 × 10−2 and molar extinction coefficient, ɛ = 29,000 ± 65 cm−1 M−1 in immobilized PVC matrix, compared to 2.6 × 10−3 and 24,573 ± 115 in ethanol solution. The offered sensor exhibited remarkable fluorescence intensity quenching upon exposure to Cu2+ ions at pH 4.0 in the concentration range of 1.0 × 10−9 to 3.0 × 10−4 M [Cu2+] while the effects of the responding ions (Ca2+, Hg+, Pb2+, Al3+, Cr3+, Mn2+, Mg2+, Sn2+, Cd2+, Co2+ and Ni2+) were less pronounced.