四环素分子印迹电化学传感器的制备及快速检测牛奶和猪肉中四环素类药物残留

Preparation of tetracycline moleculary imprinting electrochemical sensor and rapid detection of tetracycline residues in milk and pork

以四环素(TC)为模板分子,邻苯二胺(OPD)为功能单体,在磷酸缓冲液中采用电聚合的方法在玻碳电极表面制备了能够特异识别模板分子及其结构类似物的分子印迹电化学传感器。实验选用含1 mol/L KCl及5 mmol/L K_3[Fe(CN)_6]的HAc-Na Ac缓冲液为表征溶液,应用差分脉冲伏安法(DPV)和循环伏安法(CV)研究了传感器的电化学响应特性,并优化制备与检测条件。结果表明,在最佳条件下,DPV峰值电流差与四环素及其结构类似物土霉素和盐酸强力霉素在0.002~0.02 mmol/L浓度范围内线性关系良好,检出限在6.0×10^(-7)~7.5×10^(-7)mol/L之间。传感器在H_2SO_4-甲醇混合液中可再生,且具有良好的稳定性,对四环素以及结构类似物具有良好的选择性。采用该传感器对实际样品牛奶和猪肉中四环素、土霉素和盐酸强力霉素进行检测,加标回收率在82.8%~97.4%之间,相对标准偏差(RSD)≤4.43%。该传感器操作简便、检测快速灵敏、成本低,稳定性好,有良好的应用前景。

A novel molecular imprinted electrochemical sensor was prepared by electro-polymerization on the surface of a glassy carbon electrode in phosphate buffer solution, and tetracycline was used as template moleculer, o-phenylenediamine（OPD） as functional monomer.The sensor could specifically recognize the template molecule and its analogues.In the experiment,the HAc-NaAc buffer solution containing 1 mol/L KCL and 5 mmol/L K3 [ Fe（CN）6 ] was used as characterization solution, the electrochemical sensor response characteristics were researched,and the preparation and detection conditions of the sensor were optimized by differential pulse voltammetry（DPV） and cyclic voltammetry（CV）.The results showed that the sensor had a good selectivity under the optimal conditions, the linear relationships between DPV peak current difference and the concentrations of tetracycline,oxytetracycline and doxycycline hyclate were found in the range of 0.002 -0.02 mmol/L with the detection limits between 6.0× 10^-7 and 7.5 × 10^-7 mol/L.The sensor in methanoI-H2SO4 solution was renewable, and had good reproduction, stability and good selectivity to tetracycline and its analogues. The tetracycline, oxytetracycline and doxycycline in real samples,such as milk and pork,were detected by the sensor,the average recoveries were between 82.8% and 97.4%, the relative standard deviations （RSD） were less than 4.43%. This sensor was simple,sensitive,low cost,and had a good stability,which provided it a good application prospect.