Ni-sinapic acid nanocomposite in the selective sensing of permanganate ions

•Sinapic acid based synthesis of Ni-nanoparticles (NiNPs) are reported here.•The particle size of the nanoparticles were in the range 5–10 nm.•The NiNPs can selectively sense MnO4- with the limit of detection 0.41 µM in presence of co-existing ions.•The sensing mechanism was examined using isothermal titration calorimetry and X-ray photoelectron spectroscopy.•∼88 to 108 % of the added permanganate ion could be recovered from natural sample.