Herein, we developed a highly sensitive electrochemical sensor for the trace detection of Sudan I (SDI) dye based on composite molecularly imprinted membranes (MIMs). The pentenyl (lipoic acyl)-isoleucyl-chitosan oligosaccharide (P(L)ICO) and pentenyl-asparaginyl-chitosan oligosaccharide (PASCO) served as bifunctional monomer oligomers. After deposition of gold nanoparticles on a glassy carbon electrode (GCE) surface, a P(L)ICO layer successfully self-assembled on the surface. Subsequently, the primary MIM was polymerised on the electrode surface by using SDI as a template, PASCO as a functional monomer oligomer, and ethylene glycol dimethacrylate as a cross-linking agent. Electrochemical polymerisation was then conducted in an N,N′-methylenebisacrylamide solution. After eluting the SDI molecules from the composite MIMs, the fabricated SDI-MIM(PM)/Fn-Au/GCE demonstrated specific adsorption of SDI. Under optimal conditions, the constructed sensor exhibited a linear relationship between decreasing peak current and SDI concentration from 0.02 to 3.5 μM with a low detection limit of 4 nM (S/N = 3). As a proof of concept, SDI-MIM(PM)/Fn-Au/GCE was also applied to detect SDI in chili powder samples, with recoveries ranging from 96.8 to 106.6%.

中文翻译：

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基于双功能单体低聚物的复合分子印迹膜用于苏丹 I 的电化学监测

在此，我们开发了一种基于复合分子印迹膜 (MIM) 的高灵敏度电化学传感器，用于痕量检测苏丹 I (SDI) 染料。戊烯基（硫辛酰基）-异亮氨酰-壳聚糖低聚糖（P(L)ICO）和戊烯基-天冬酰胺基-壳聚糖低聚糖（PASCO）作为双功能单体低聚物。在玻璃碳电极 (GCE) 表面上沉积金纳米颗粒后，P(L)ICO 层成功地在表面上自组装。随后，以SDI为模板，PA​​SCO为功能单体低聚物，乙二醇二甲基丙烯酸酯为交联剂，在电极表面聚合初级MIM。然后在N , N中进行电化学聚合'-亚甲基双丙烯酰胺溶液。从复合 MIM 中洗脱 SDI 分子后，制备的 SDI-MIM(PM)/Fn-Au/GCE 表现出对 SDI 的特异性吸附。在最佳条件下，构建的传感器在峰值电流和 SDI 浓度从 0.02 到 3.5 μM 之间呈现线性关系，低检测限为 4 nM (S/N = 3)。作为概念验证，SDI-MIM(PM)/Fn-Au/GCE 也被用于检测辣椒粉样品中的 SDI，回收率在 96.8% 到 106.6% 之间。