Ammonium heptamolybdate preloaded on flexible carbon-matrix film electrode for the electrochemical phosphate sensor in a river water sample

•AHM@PANI/CC/PVDF composite flexible film electrode was prepared for sensing H2PO4−.•The interaction of AHM with PANI/CC/PVDF was confirmed by spectroscopic techniques.•Chemical reaction product, Keggin-type phosphomolybdic complex, was determined by CV.•AHM@PANI/CC/PVDF electrode can be used to detect H2PO4− in the range of 10–114 µM.