Electrospun curcumin-loaded zein membrane for iron(III) ions sensing

Zein membrane containing curcumin, fabricated by electrospinning and amide crosslinking by a heat-induced process with citric acid, was evaluated as a new optical sensor for Fe3+ ions. The concentration of Fe3+ in aqueous solution was determined by naked-eye detection after dipping the membrane into the sample solution. In the presence of Fe3+, the color of membrane changed from yellow to brown. The effects of solution pH and co-existing metal ions (Ag+, Cd2+, Co2+, Cr3+, Cu2+, Fe2+, Hg2+, Mn2+, Ni2+, Pb2+, Zn2+, Ba2+, Mg2+, Ca2+, Na+, K+ and As5+) were investigated. It was found that the Fe3+ determination using 5% w/w (curcumin/zein) fabricated membrane in a solution at pH 2 showed high efficiency visual sensing without any significant interfering. Its optical detection limit was 0.4 mg/L which is lower than the maximum acceptable concentration in potable water. The proposed sensing method demonstrated good accuracy upon the results obtained by inductively coupled plasma optical emission spectrometry (ICP-OES). (C) 2014 Elsevier B.V. All rights reserved.