中空花生形NiFe2O4/CoFe2O4孪晶纳米球壳复合材料具有互连的电子通道和优异的电化学性能,这促使使用这种独特的空间结构来制造高效的电化学传感器。在这项工作中,将N掺杂碳点(NCD)掺入磁性NiFe2O4/CoFe2O4纳米颗粒壳(NiFe2O4/CoFe2O4/NCD)修饰的玻碳电极(GCE)中,以构建基于双模板分子印迹聚合物(MIP)的电化学传感器(NiFe2O4/CoFe2O4/NCD/MIP/GCE),用于同时检测儿茶素(CA)和PH。通过理论探索和密度泛函理论(DFT)计算机定向模拟的原位电化学聚合策略,筛选出最佳功能单体(L-精氨酸)和双模板分子(CA和TPH)与功能单体之间的最佳比例。用SEM对材料进行了表征,TEM,XRD,XPS,和TGA。此外,电子结合能,结合常数,并对印迹因子进行了研究。在最优条件下,提出的电化学双检测系统显示出优异的分析性能,同时检测CA和TPH,具有超低的检测限(LOD,S/N=3)在0.01-1μM(R2=0.9956)和1-50μM(R2=0.9928)的CA中为1.3nM,以及在0.1-100μM的线性范围内TPH的20.0nM的LOD(R2=0.9939),分别。此外,用差分脉冲伏安法和计时电流法测试了传感器的选择性和抗干扰性能,并成功检测了茶饮料和人体尿液样品中的分析物,回收率在98.22%至104.76%之间,相对标准偏差(RSD)为1.19%-3.81%,证明了传感器具有出色的稳定性,重复性,和再现性,这为其他平台使用这种纳米材料在现场食品安全中检测抗氧化剂铺平了道路。
Hollow peanut-shaped NiFe2O4/CoFe2O4 twinned nano-spherical shell composite materials have interconnected electron channels and excellent electrochemical performance, which prompted the use of this unique spatial structure to fabricate efficient electrochemical sensors. In this work, N-doped carbon dots (NCDs) incorporated into magnetic NiFe2O4/CoFe2O4 nanoparticle shell (NiFe2O4/CoFe2O4/NCDs) modified glassy carbon electrode (GCE) was applied to construct a dual-template molecularly imprinted polymer (MIP) based electrochemistry sensor (NiFe2O4/CoFe2O4/NCDs/MIP/GCE) for the simultaneous detection of catechin (CA) and theophylline (TPH). MIP was fabricated by an in-situ electrochemical polymerization strategy based on the theoretical exploration and density functional theory (DFT) computer directional simulation to screen out the optimal functional monomer (L-arginine) and the optimal ratio between the dual template molecules (CA and TPH) and functional monomer. The materials were characterized by SEM, TEM, XRD, XPS, and TGA. Besides, electron binding energy, binding constant, and imprinting factor were investigated. With the optimal conditions, the proposed electrochemical dual detection system showed outstanding analytical performance for the simultaneous sensing of CA and TPH, with an ultralow detection limit (LOD, S/N = 3) of 1.3 nM for CA in 0.01-1 μM (R2 = 0.9956) and 1-50 μM (R2 = 0.9928), as well as a LOD of 20.0 nM for TPH in the linear range of 0.1-100 μM (R2 = 0.9939), respectively. Also, the selectivity and anti-interference performances of the fabricated sensor were performed by differential pulse voltammetry and chronoamperometry, and successfully detected the analyte from tea drinks and human urine samples with the recovery rates ranging from 98.22% to 104.76% and relative standard deviations (RSD) were 1.19%-3.81%, demonstrated the sensor has excellent stability, repeatability, and reproducibility, which paves the way for other platforms to use this nanomaterial for the detection of antioxidant in the filed food safety.