Rhodamine-based conjugated polymers: potentiometric, colorimetric and voltammetric sensing of mercury ions in aqueous medium

Ayranci R., Demirkol D. , TİMUR S. , Ak M.

ANALYST, vol.142, no.18, pp.3407-3415, 2017 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 142 Issue: 18
  • Publication Date: 2017
  • Doi Number: 10.1039/c7an00606c
  • Title of Journal : ANALYST
  • Page Numbers: pp.3407-3415


Herein, we report the synthesis and characterization of a new rhodamine-based monomer (RD-CZ), and an investigation of the optical and electrochemical properties of the corresponding polymer (P(RD-CZ)),which was electropolymerized on an ITO electrode. The resulting P(RD-CZ) polymer film was used as a simple and novel multi-signal sensor platform, which demonstrates ion-selective potentiometric, colori-metric and voltammetric responses in aqueous media for the first time. P(RD-CZ) exhibits excellent selectivity for Hg2+ ions compared with Cd2+, Cu2+ Zn2+, and Fe3+ using the potentiometric technique, which depends on the increasing charge carrier transport through rhodamine-bound Hg2+ with a limit of detection (LOD) of 9.77 x 10(-8) M. The P(RD-CZ) polymer film also exhibits a distinct color change from orange to purple, which is detectable even by the naked eye, in the presence of Hg2+ ions. The LOD for Hg2+ ions obtained using the colorimetric method is 3.16 x 10(-8) M. The same material has also been used for the voltammetric sensing of Hg2+ in aqueous media with a detection limit of 1 x 10(-7) M. In this study, a conductive polymer-based sensor platform for detecting mercury ions via three different methods has been designed for the first time. By doing so, a disposable planar paper-based ion-sensing platform, which is suitable for low-cost point-of-care and in-field testing applications, could be fabricated with a highly reproducible and linear response towards different concentrations of analyte ions in aqueous and biological samples.