Effective solid contact for ion-selective electrodes: tetrakis(4-chlorophenyl)borate (TB-) anions doped nanocluster films.

We report on a novel material, tetrakis(4-chlorophenyl)borate (TB(-)) anion doped nanocluster films, as the solid contact (SC) for producing well-defined, electrochemically reversible, and nonpolarizable double interfaces on it. Detailed studies have unambiguously revealed that, for the first time, the developed SC can fully overcome all the signal stability problems of ion-selective electrodes (ISEs), offering a reliable and universal platform for the development of high quality SC-ISEs. As an exemplification, the developed monolayer-protected cluster (MPC) based K(+)-ISEs have advantages of excellent analytical performances, e.g., the low potential drift (10.1 ± 0.3 μV h(-1) over 72 h measured in 0.1 M KCl and 10.8 ± 0.5 μV h(-1) over 96 h rechecked in 0.1 M KCl after 1 month) and the stable and reproducible linear range, sensitivity, and standard potential (few changes within the first 6 weeks). This evidence suggests that the developed MPC films are the most promising SC transducers among all the reported ones to the best of our knowledge.