An overview of the molecular sensors developed for the recognition of inorganic phosphate

Inorganic phosphate (Pi) anions play key roles in numerous biological and chemical processes. This critical review focuses on the development of chemosensors for inorganic phosphate, being either fluorescent and/or colorimetric. Throughout the previous few years, several exciting results have been developed for the recognition of this biologically important anionic species. The review commences with a short description about the importance of recognition of phosphate followed by a classification of the sensors according to their strategies of sensing. The state of art of Pi recognition involved mainly two major mechanisms such as hydrogen bonding and coordination chemistry. Various processes, namely displacement assay, aggregation-induced emission, excimer formation, panchromatic emission etc. are being exploited for Pi recognition with associated optical changes triggered by different photo-induced processes. For, this, receptor design plays an important role in achieving the desired optical (electronic and/or luminescence) changes for recognition and quantification of Pi. This critical review focuses on the fluorescent or colorimetric sensors for inorganic phosphate (Pi). These sensors used several binding strategy viz. Hydrogen bonding, ionic interaction and coordination interaction for the selective Pi detection. [Display omitted]