NiCu nanoalloy embedded in N-doped porous carbon composite as superior electrochemical sensor for neonicotinoid determination

Enhancing catalytic activity is the key to develop electrochemical sensors for monitoring of neonicotinoid such as imidacloprid (IMI), thiamethoxam (THX) and dinotefuran (DNF). Herein, a MOF-derived octahedral NiCu nanoporous carbon composite with abundant N-doped (N/NiCu@C) was synthesized, which was exploited as electrochemical sensor for neonicotinoid determination. Integrating the synergistic effect of NiCu nanoalloy and the hierarchical porous carbon structure, the N/NiCu@C/GCE significantly promoted the diffusion between electrolyte and active site. Meanwhile, the introduction of polyvinylpyrrolidone (PVP) improved the hydrophilicity and dispersibility of N/NiCu@C, endowing superior electrocatalytic performance for IMI, THX and DNF determination, with linear ranges of 0.5-60, 1-60 and 0.5-60 μM, respectively, and detection limits of 0.017, 0.007 and 0.001 μM. Additionally, the sensor can determine IMI, THX and DNF in apples, tomatoes and potatoes with the recovery rate of 92.1-103.4% and RSD ≤ 4.7%. This study has explored a novel modified electrode material for construction of neonicotinoid sensors.