Electrochemical sensing platform for hydrogen peroxide using amorphous FeNiPt nanostructures

Amorphous ternary FeNiPt nanomaterials with tunable length are reported for constructing the electrochemical sensing platform, in which hydrogen peroxide (H₂O₂) is selected as a model target. It is found that amorphous FeNiPt nanostructures, in particular, the FeNiPt nanorods with large axial-ratio (FeNiPt-NRL) exhibit the enhanced electrocatalytic activity towards both the oxidation and reduction of H₂O₂. Meanwhile, the comparable corrosion potential E_corr and lower corrosion current I_corr are observed at GC electrodes modified with FeNiPt-NRL, revealing the good stability of the FeNiPt-NRL surface. On the basis of these results, H₂O₂ is cathodically determined at glassy carbon (GC) electrodes with FeNiPt-NRL with relatively high selectivity at the appropriate potential of 0 V vs. AgAgCl. On the other hand, the sensitivity of the anodic H₂O₂ detection at the same electrode is achieved to be 2.45 mA cm^-2 mM^-1, which is 4-fold larger than that of the cathodic detection and those Pt nanoparticles-based H ₂O₂ determination, and the detection limit is also developed to 40 nM. The dynamic linear range is broadened from 100 nM to 30 mM, which is wider than those H₂O₂ detection based on Pt nanoparticles and binary Pt alloys. In addition, electrochemical results show the high stability and good reproducibility for the present H₂O ₂ sensor. The striking analytical performance combined with the intrinsic properties of amorphous FeNiPt nanomaterials provides a promising technique for the development of non-enzyme H₂O₂ and other molecule sensors with high sensitivity, broad dynamic linear range, long stability, and good reproducibility.