钯纳米粒子修饰的三甲氧苄啶分子印迹膜传感器的制备及其识别性能研究

采用N,N′-亚甲基双丙烯酰胺(MBA)为功能单体、钯纳米粒子为掺杂剂、马来松香丙烯酸乙二醇酯为交联剂,在玻碳电极上热聚合具有三甲氧苄啶(TMP)识别性能的钯纳米材料修饰的分子印迹传感膜.采用扫描电镜及红外光谱对合成的钯纳米材料、印迹传感膜的形貌及其结构进行了表征;采用循环伏安法(CV)、交流阻抗法(EIS)对钯纳米粒子掺杂的印迹电极与无掺杂电极的电化学性能进行了研究.结果表明,纳米粒子掺杂的印迹电极与无掺杂电极的表面形貌及电化学性能明显不同.差分脉冲伏安法(DPV)表征结果表明,TMP的浓度在5.0×10-7~4.0 ×10-3 mol/L范围内与脉冲峰电流呈良好的线性关系(R=0.9995),检出限为3.2×10-8 mol/L (S/N=3).此钯纳米粒子掺杂的印迹传感器具有较高的灵敏度.即时电流测定结果表明,新诺明(SMZ)、磺胺嘧啶(SDZ)、葡萄糖 (Glu)、尿素 (Urea)对三甲氧苄啶(TMP)的测定不产生干扰.将此印迹传感器用于实际样品中TMP的检测,加标回收率为96.8%~102.0%.

Preparation and Recognition Properties of Trimethoprim Sensor Based on Palladium Nanoparticles-modified Molecularly Imprinted Polymer

To improve the sensitivity of molecularly imprinted electrochemical sensors, a Pd nanoparticles-modified molecularly imprinted polymer (MIP) film for the determination of trimethoprim (TMP) was developed by thermal polymerization with N, N′-methylene diacrylamide as a functional monomer, Pd nanoparticle as a dopant and ethylene glycol maleic rosinate acrylate as a crosslinking agent.The morphologies and chemical structures of the Pd nano-materials and the imprinted films were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy, respectively.The electrochemical properties of the nano-doped and undoped MIP sensors were investigated by cyclic voltammetry and electrochemical impedance spectroscopy.Results showed that the morphologies and chemical structures and the electrochemical properties of the doped molecularly imprinted sensor were remarkably different from those of the undoped imprinted sensor.Linear responses of the imprinted sensor to TMP were observed for concentrations ranging from 5.0×10-7 mol/L to 4.0×10-3 mol/L (R=0.9995), with a detection limit of 3.2×10-8 mol/L (S/N=3).The Pd nanoparticle doped MIP sensors exhibited high selectivity.The chronoamperometry showed that no interference from potential interfering species such as sulfamethoxazole, sulfadiazine, glucose, and urea were noted.The proposed electrochemical sensor was used to determine TMP in actual samples, with average recoveries of 96.8%-102.0%.