Selective fluorescent sensors of important (condensed) phosphates, such as Pi and pyrophosphate (PPi), have been developed using different strategies, including hydrogen bonding interaction, coordination chemistry, displacement assay/decomplexation, and aggregation-induced emission/quenching. The choice of using an ESIPT-based strategy is promising due to its current success in detection of numerous environmentally and biologically significant analytes. 18a, 19 However, achieving selective detection of polyP over PPi and other anions like nucleotides is not a trivial task. Moreover, the sensor should rapidly respond in an aqueous environment. This adds a solubility problem, as a majority of the known ESIPT based fluorescence sensors are only sparingly soluble in aqueous solution, which limits their widespread applicability. 20 Herein, we report the first chemoselective, reversible, water-soluble, short chain inorganic polyP sensors that work in an aqueous environment and rely on the ESIPT mechanism providing large Stokes-shifts for diverse applications.