Colorimetric Calcium Probe with Comparison to an Ion-Selective Optode Changyou Zhu Manling Huang Jialing Lan Lung Wa Chung Xin Li Xiaojiang Xie 10.1021/acsomega.8b01813.s001 https://acs.figshare.com/articles/journal_contribution/Colorimetric_Calcium_Probe_with_Comparison_to_an_Ion-Selective_Optode/7159646 Design strategies for small molecular probes lay the foundation of numerous synthetic chemosensors. A water-soluble colorimetric calcium molecular probe inspired by the ionophore-based ion-selective optode is presented here with a tunable detection range (around micromolar at pH 7). The binding of Ca<sup>2+</sup> resulted in the deprotonation of the probe and thus a significant spectral change, mimicking the ion-exchange process in ion-selective optodes. The 1:1 exchange between Ca<sup>2+</sup> and H<sup>+</sup> was confirmed with Job’s plot. Computational studies revealed possible monomer and dimer forms of the probe–Ca<sup>2+</sup> complexes. 2018-10-03 08:13:36 probe colorimetric calcium ion-exchange process dimer forms Computational studies tunable detection range Ion-Selective Optode Design strategies ion-selective optodes Colorimetric Calcium Probe ionophore-based ion-selective optode