电聚合制备三聚氰胺分子印迹QCM传感器薄膜及其表征研究

通过研究得出,在聚合电压U为0～1.6V、聚合段数为22、模板三聚氰胺(MEL)浓度为4mmol/L、单体甲基丙烯酸(MAA)浓度为10mmol/L、成膜剂邻苯二胺(o-PD)浓度为18mmol/L条件下,以pH 8.0的BR缓冲液作为溶剂和电解液,用电聚合方法,直接在石英晶体微天平(QCM)传感器电极上修饰的分子印迹薄膜,其对目标分子MEL具有良好的频率表征效果,频移值为59Hz。通过相同3个修饰电极的频率表征变化来看,电极对目标分子的识别表征极不稳定。这与手动进样方式、环境较大噪声和电极本身差异密切相关,难以建立对目标分子的标准曲线(r=0.966)实现准确定量分析。

Electropolymerization for Preparation of Melamine Molecularly Imprinted QCM Sensor Membrane and Its Characterization

Molecularly imprinted membrane for direct modification of QCM sensor electrode was prepared by electropolymerization using BR buffer(pH 8.0) as the solvent and the electrolyte solution under the conditions of 0–1.6 V,22,4 mmol/L,10 mmol/L and 18 mmol/L for polymerization voltage,the number of polymeric segments,template(melamine,MEL) concentration,monomer(methacrylic acid,MAA) concentration and o-PD(film-forming agent) concentration,respectively,The prepared membrane had good performance for frequency characterization of MEL with frequency shift of 59 Hz.Three replicates of the modified QCM sensor electrode showed variations in frequency characterization,suggesting its very poor stability,which may be closely related to manual sampling,the high level of environmental noise and the electrode itself.As a result,it is hard to establish a standard curve for accurate quantification of melamine.