NiCo-embedded in hierarchically structured N-doped carbon nanoplates for the efficient electrochemical determination of ascorbic acid, dopamine, and uric acid

Abstract

The development of a highly stable and efficient catalyst for sluggish electrooxidation in the electro-determination for ascorbic acid (AA), dopamine (DA) and uric acid (UA) is extremely important for the long-term operation and commercialization of a biosensor device, but it remains a challenge. Herein, we demonstrated an interesting structure of NiCo alloy nanocrystals embedded in hierarchically structured N-doped carbon nanoplates (NiCo-NPs-in-N/C), which is facilely synthesized via a one-step in situ reduction pyrolysis strategy. The two-dimensional N-doped porous carbon shells not only offered the effective confinement effect of NiCo nanocrystals avoiding detachment, dissolution, migration, and aggregation during catalysis process, but also allowed a fast transport pathway for the access of electrolyte to the NiCo surface. As a result, such an intriguing structure shows superior catalytic activity towards the electrooxidation of AA, DA, and UA. The well-separated voltammetric peaks between AA–DA, DA–UA, and AA–UA at the NiCo-NPs-in-N/C are up to 178, 122, and 300 mV, respectively, which is much better than graphene@N-doped carbon core@shell nanoplate (graphene@N/C) and NiCo alloy. Furthermore, the NiCo-NPs-in-N/C also exhibits good reproducibility and stability. The attractive features of NiCo-NPs-in-N/C make it a promising electrocatalyst for the simultaneous determination of AA, DA, and UA.