基于分子印迹聚合物的微流控化学发光传感器检测莱克多巴胺

A microfluidic chip-chemiluminescence sensor based on molecular imprinted recognition for determination of ractopamine

目的：制备能特异性识别莱克多巴胺(ractopamine, RCT)的分子印迹聚合物(molecularly imprinted polymers, MIPs),将该印迹聚合物与微流控化学发光法结合起来,以制备高选择性的化学发光传感器。方法利用沉淀聚合法制备莱克多巴胺印迹聚合物,采用扫描电镜、红外光谱法、吸附实验对其进行表征；以该印记聚合物为识别元件,以微流控芯片为流通反应池,并以化学发光仪作为检测器,通过流动注射分析法来检测猪肝和牛肉中的莱克多巴胺。结果在最佳条件下,测得莱克多巴胺线性范围6～960 ng/mL,线性回归方程为?I=4.8777C-9.7851, r=0.9907,检出限为0.83 ng/mL,对10 ng/mL莱克多巴胺平行测定11次,其RSD(相对标准偏差)为7.1%。应用该方法成功分析了猪肝和牛肉中RCT含量,回收率可达90.3%~99.8%。结论本方法快速、准确、样品前处理简单,能很好地用于食品中莱克多巴胺残留的检测。

Objective A ractopamine (RCT) imprinted polymer was prepared as a recognition element, which had the ability of specific recognition. Based on the recognition element, a novel microfluidic chip-chemiluminescence(CL) sensor was designed and assembled to monitor the RCT content in food. Methods The RCT imprinted polymer was synthesized by precipitation polymerization. SEM, FT-IR spectra and absorption experiment were applied as characterization methods. With MIPs working as the recognition element, microfluidic chip as flow reaction cell, a novel flow analysis CL sensor for the determination of RCT was developed and optimized. Results Under the optimal conditions, the relative CL intensity showed a linear relationship in the range of 6～960 ng/mL RCT with detection limit of 0.83 ng/mL. The linear regression equation was ΔI=4.8777C-9.7851, r=0.9907. The relative standard deviation was 7.1% for 10 ng/ mL RCT (n=11). The method was successfully used to analyze the RCT content in pig liver and beef. The recovery was between 90.3% and 99.8%. Conclusion The method is rapid, accurate, and simple pre-treatment, which can be well used in the determination of ractopamine residues in food.