Abstract
A hydrogel sensing film for a real-time and indicator-free detection of Zn 2+ is developed by embedding a fluorescent indicator 11,16-bis(phenyl)-6,6,21,21-tetramethyl-m-benzi-6,21-porphodimethene in a hydrogel host poly(2-hydroxyethyl methacrylate). The sensing film shows high stability and selectivity to Zn 2+ . The sensitivity of the sensing film is increased by fabricating a micron-sized pillar array on the surface of the sensing film to increase the surface area. For Zn 2+ concentrations of 10 -4 and 10 -3 M, the response time is 30 and 3 s, respectively. © 2011 Elsevier B.V. All rights reserved.