Yongfeng Chen ,Shixin Li,Rui Gao,Yujie Shi,Yufeng Sun,Geoffrey I.N. Waterhouse,Zhixiang Xu

Abstract

Herein, we synthesized a novel injectable porous magnetic hydrogel (MHG) at room temperature using carboxymethyl chitosan (CMCS), polydopamine (PDA), sodium alginate (SA), polyethyleneimine (PEI) and copper ferrite (CuFe2O4) as building blocks. The CMCS and SA as monomers provided good film-forming and anti-fouling properties for MHG. The PDA-coated CuFe2O4 as a cross-linking agent improved the homogeneity, adsorption and electrocatalytic performance of MHG, but also generated a macroporous hydrogel structure which was beneficial for sensing applications. The positive PEI enhanced the adsorption of nitrite (NO2−) via electrostatic attraction. The MHG modified glassy carbon electrode (MHG/GCE) sensor offered a wide linear range (0.02–2250.00 μM) and a low limit of detection (3.60 nM) for NO2−. Recovery tests in crispy fried pork and roast chicken yielded excellent recoveries (91.01 %–107.68 %). Analyses of commercial chicken sausage and canned luncheon meat were conducted using the MHG/GCE sensor and an ultraviolet spectrophotometry method, with the results being near identical.

Paper Linkage:https://doi.org/10.1016/j.foodchem.2025.143030