A novel Salamo-Salen-Salamo hybrid Mg(II) complex fluorescent chemosensor for highly effective monitoring H2PO4ˉ in Zebrafish and plants

•A simple and effective Salamo-Salen-Salamo-Mg sensor MT was successfully developed and characterized.•MT of violent blue fluorescence functions as a highly H2PO4− selective sensor based on a fluorescence quenching signals with almost no interference of competitive ions.•Sensor MT was successfully studied using solid-state fluorescence of paper test under 365 nm UV lamp.•Bioimaging analysis demonstrated that MT could act as a sensor to monitor the level of H2PO4ˉ in living biological systems including Zebrafish and bean sprouts.