A novel NBD-phenoxo-bridged dinuclear Zn(II) complex is found to be an effective colorimetric sensor for pyrophosphate (PPi) in pure aqueous solution over a wide pH range. This sensor shows high binding affinity (Ka ≈ 3 × 108 M−1) and high selectivity for PPi, and can be also used to assay the activity of pyrophosphatase in real time.
