Cation Effect on Fluorescent Sensing of Pyrophosphate by a Bis(Zn–DPA) Probe

Figure S1 Spectral changes of 1·2Zn (8 μM) with increasing concentration of ATP in 50 mM HEPES buffer (pH 7.4) in the presence of (a) no ion, (b) 100 mM NaCl, (c) 5 mM MgCl₂, (d) 5 mM CaCl₂.

Figure S2. Spectral changes of 1·2Zn (8 μM) with increasing concentration of PPi in 50 mM HEPES buffer (pH 7.4) in the presence of (a) 24 μM ATP, (b) 100 mM NaCl and 24 μM ATP, (c) 5 mM MgCl₂ and 32 μM ATP, (d) 5 mM CaCl₂ and 32 μM ATP.

Figure S3. Spectral changes of 1·2Zn (8 μM) with increasing concentration of PPi in 50 mM HEPES buffer (pH 7.4) in the presence of (a) no ion, (b) 100 mM NaCl, (c) 5 mM MgCl₂, (d) 5 mM CaCl₂.

Figure S4. Representative fitting results of I₄₇₀ against (a) [ATP], (b) [PPi] in the presence of 24 μM ATP, and (c) [PPi] in 50 mM HEPES buffer (pH 7.4).

Figure S5. Representative fitting results of I₄₇₀ against (a) [ATP], (b) [PPi] in the presence of 24 μM ATP, and (c) [PPi] in 50 mM HEPES buffer (pH 7.4) containing 100 mM NaCl.

Figure S6. Representative fitting results of I₄₇₀ against (a) [ATP], (b) [PPi] in the presence of 32 μM ATP, and (c) [PPi] in 50 mM HEPES buffer (pH 7.4) containing 5 mM MgCl₂.

Figure S7. An energy-minimized structure of the complex of ATP with 1·2Zn (without a naphthyl group) shown in a stick model (left) and a space-filling model (right).

Figure S8. An energy-minimized structure of the complex of ATP with 2·Zn₂ shown in a stick model (left) and a space-filling model (right).

Table S1. Comparison of log K_a,PPi – log K_a,ATP (difference of two individual log K_a’s) and log K_PPi/K_ATP (obtained by competition experiment).

Table S2. Calculated association constants (log K) between 1·2Zn and analytes according to competitive binding of a host and an ion to a guest.

Appendix S1. Fitting methods and references.