An organic hydrogel film with micron-sized pillar array for real-time and indicator-free detection of Zn2+

A hydrogel sensing film for a real-time and indicator-free detection of Zn2+ 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 Zn2+. 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 Zn2+ concentrations of 10−4 and 10−3 M, the response time is 30 and 3 s, respectively.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We realized an organic hydrogel sensing film specific to Zn2+. ► The organic hydrogel sensing film shows high stability and selectivity. ► Micron-sized pillar arrays are fabricated on the surface of the sensing film to increase the surface area. ► The response time is as fast as 3 s when Zn2+ concentration is 10−3 M.