An organically modified sol-gel membrane for detection of mercury ions by using 5,10,15,20-tetraphenylporphyrin as a fluorescence indicator

A new optical sensor membrane for sensing of Hg2+ in aqueous solution has been developed by using (5,10,15,20-tetraphenylporphyrin, H2tpp) as a lipophilized indicator, which was dissolved in an organically modified sol-gel. The method for preparation of this organically modified sol-gel membrane and its characteristics were investigated in detail. The fluorescence quenching of the sol-gel membrane by Hg2+ showed a linear response over the Hg2+ concentration range of 5.0 x 10(-6) to 1.0 x 10(-4) mol/l with a detection limit of 3.6 x 10(-6) mol/l, and the good stability, reversibility, long lifetime and short response time could be obtained. (c) 2005 Elsevier B.V. All rights reserved.