目的：制备一种可用于选择性识别黄芩苷的分子印迹聚合物，并构筑电化学传感器，实现对黄芩苷的特异性电化学检测。方法以丙烯酰胺作为功能单体，偶氮二异丁腈作为引发剂，乙二醇二甲基丙烯酸酯作为交联剂，黄芩苷作为模板分子，本体聚合法制备分子印迹聚合物。利用扫描电镜对其结构进行鉴定，利用循环伏安法和差分脉冲伏安法对传感器的电化学行为进行考察。结果该分子印迹聚合物对黄芩苷具有良好的特异性吸附性能，印迹材料的电化学响应是非印迹材料的3．5倍；相比于其他结构相似的分子（芒柄花苷、黄芩素、汉黄芩素、汉黄芩苷等），该传感器对黄芩苷表现出了良好的选择性。在最优化条件下，电流响应与黄芩苷的浓度在1．5～60μmol／L范围内呈现良好的线性关系（r≥0．998），最低检测限为0．6μmol／L （S／N≥3）。对复方蒲芩胶囊中黄芩苷有效成分的检测回收率为97．14％～100．01％。结论该印迹材料的制备方法简单，实现了复杂中药中主要有效成分的选择性检测。%Objective To prepare a molecular imprinting polymer ( MIP) which can selectively recognize baicalin and to construct an electrochemical biosensor for selective electrochemical determination of baicalin.Methods A MIP was synthesized using acrylamide as a functional monomer, azodiisobutyronitrile as an initiator, ethylene glycol dimethyl acrylic ester ( EGDMA) as a cross-linking agent and baicalin as a template molecule.Then, its structure was identified by scanning electronic microscopy ( SEM) .Meanwhile, its electrochemical properties were characterized by cyclic volta-mmetry ( CV ) and differential pulse voltammetry ( DPV ) .Results The resultant MIP displayed specific absorptive properties toward baicalin.The electrochemical responses obtained by the MIP were 2.5 times higher than those of non-imprinting polymers ( NIPs) .Moreover, the modified biosensor could specifically recognize baicalin compared with other four structurally-similar molecules, including ononin, baicalein, wogonin and wogonoside.A good linear relationship was showed between current responses and the concentrations of baicalin from 1.5 to 60 μmol/L (r≥0.998), with a minimum detection limit (LOD) of 0.6 μmol/L (S/N≥3).The recovery of baicalin in Compound PuQin capsules was 97.14%to 100.01%.Conclusions The proposed preparation is each to operate, and can achieve a high selectivity to-wards ingredients in herbal compounds.
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