In this work, Pt, Fe and Co nanoparticles were prepared by chemical reduction of the metal salts in chitosan as the support. NaBH4 was used as the reducing agent Pt-Fe, Pt-Co and Pt-Fe-Co-chitosan nanocomposites were synthesized and characterized by UV–Vis spectra and Transmission electron microscopy images. GC/Pt-chitosan, GC/Pt-Co-chitosan, GC/Pt-Fe-chitosan and GC/Pt-Co-Fe-chitosan electrode...