【作者】 张进；

【导师】 徐岚；

【作者基本信息】 西南大学 ， 分析化学， 2010， 硕士

【摘要】 分子印迹聚合物(MIP)是一种具有分子识别能力的新型高分子材料,人工合成的分子印迹聚合物极为稳定,在较苛刻的条件如高温、有机溶剂、酸碱等条件下仍能保持较好的识别能力。但由于传统方法合成的分子印迹聚合物制备的膜较厚、识别位点被深埋在颗粒内部,导致传感器再生困难、响应时间长、灵敏度低等缺陷。这些给分子印迹技术在电化学传感器中的应用带来困难。针对传统印迹方法的缺点,本论文将自组装法、电聚合法、纳米技术与分子印迹技术相结合,分别制备了双酚A和妥拉苏林分子印迹电化学传感器,在一定程度上克服了传统印迹聚合物的固有缺点。具体工作如下：1.基于分子印迹电聚合膜的双酚A电化学传感器以双酚A为模板分子,邻氨基苯硫酚为单体,采用自组装和电聚合方法,在电极表面制备了对双酚A有选择性的分子印迹聚合物膜。通过循环伏安法研究传感器对双酚A的响应特性,结果表明在6.0x10-7～5.5x105 mol·L-1(r=0.991)浓度范围内峰电流值与浓度呈良好线性关系,检测限为2.0×10-7 mol·L-1,相对标准偏差小于5%(n=9),达到稳定电流所用时间约2 min。该传感器具有良好的选择性、重现性及稳定性。通过交流阻抗技术和计时电流法表征了电极表面膜的电化学性质。将传感器初步用于实际样品的分析,获得了较满意的结果。2.妥拉苏林分子印迹膜传感器的制备及识别特性研究用电聚合的方法在金电极上制备了以妥拉苏林为模板分子的自组装邻氨基硫酚分子印迹膜传感器。通过差分脉冲伏安法研究传感器对妥拉苏林的响应特性,结果表明：在优化的实验条件下,此传感器的峰电流响应值与妥拉苏林浓度在0.4-5μg·mL-1(r=0.9986)和5～120μg·mL-1(r=0.9953)范围内保持良好的线性关系；检测限为0.18μg·mL-1；相对标准偏差约为2.47%,响应时间约为3 min。传感器具备较好的选择性和稳定性。将传感器初步用于人体尿液中妥拉苏林的分析,获得了较满意的结果。3、基于纳米金-印迹聚邻氨基硫酚复合膜的妥拉苏林电化学传感器的研制结合分子印迹技术和电聚合方法,在金电极表面制备了用于检测妥拉苏林的纳米金-聚邻氨基硫酚复合膜传感器。采用交流阻抗和循环伏安法表征了传感器的制备过程,通过K3Fe(CN)6探针分子研究了目标分子和识别位点间的相互作用。实验结果表明：在优化的实验条件下,K3Fe(CN)6的峰电流值与妥拉苏林的浓度在0.05～5.0μg·mL-1和5.0～240μg·mL-1范围内呈线性关系,检测下限为0.016μg·mL-1。此外,研制的传感器具有较好的选择性和稳定性。灵敏度提高的原因可能是纳米金降低了电子间的转移阻抗。更多还原

【Abstract】 Molecularly imprinted polymer(MIP) is a new kind of macromolecular material with high molecular recognition characteristic. Furthermore, synthetic MIPs are highly stable and able to bear high temperature, acid or alkaline condition, and organic solution. The MIPs made in traditional ways, however, are usually thick and recognition sites are buried deep inside the particles, which introduce difficulties for electrochemical sensing application, such as bad reversibility and reproducibility, long analysis time intervals and low sensitivity, etc. To overcome some of the difficulties associated with traditional MIPs matrices, electrochemical sensors for the detection of bisphenol A and tolazoline are constructed successfully in the thesis by coupling self-assembly, electropolymerization with molecular imprinting technology.The details are as follows:1. Electrochemical Sensor for Bisphenol A Based on Molecular Imprinting Technique and Electropolymerization MembraneBy using the approach of self-assembly and electropolymerization, molecularly imprinted polymer membrane for Bisphenol A has been synthesized with Bisphenol A as template molecule,o-Aminothiophenol as functional monomer. Based on which, an electrochemical sensor was constructed and its response to BPA was evaluated by cyclic voltammetry. The peak current intensity was linear to Bisphenol A in the range from 6.0×10-7 to 5.5×10-5 mol·L-1 with a detection limit of 2.0×10-7 mol/Land the RSD< 5%(n=9). The response time of stable current was about 2 min. The proposed sensor also exhibited good selectivity, reproducibility and stability. The AC impedance technology and chronoamperometry were employed to study the electrochemical Characteristic of the membrane. The sensor was successfully applied to the determination of BPA in several sample.2. Preparation and Characterization of Tolazoline Sensor Based on Molecularly Imprinted PolymerA novel electrochemical sensor for the detection of tolazoline based on molecularly imprinted polymer of electropolymerized o-aminothiophenol onto gold electrode was constructed. Its response to tolazoline was evaluated by differential pulse voltammmograms(DPV). Under the optimized conditions, the response current of the proposed sensor decreased linearly in two concentration ranges of tolazoline from 0.4 to 5μg-mL-1 (r=0.9986) and from 5 to 120μg·mL-1(r=0.9953) with a detection limit of 0.18μg·mL-1. The RSD was about 2.47%and the response time was closed to 3 min. Moreover, the studied imprinted sensor exhibited high selectivity and long-term stability. The sensor was successfully applied to the determination of tolazoline in human urine samples.3. Electrochemical Tolazoline Sensor Based on Gold Nanoparticles and Imprinted Poly-o-aminothiophenol FilmAmperometric detection of tolazoline (TL) was carried out on a gold nanoparticles (AuNPs)/poly-o-aminothiophenol (PoAT)-modified electrode by a molecular imprinting technique and electropolymerization method. The modification procedure was characterized via electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The recognition between the imprinted sensor and target molecule was observed by measuring the variation of amperometric response of the oxidation-reduction probe, K3Fe(CN)6 on electrode. Under the optimal experimental conditions, the peak currents were proportional to the concentrations of tolazoline in two ranges of 0.05 to 5.0μg·mL-1 and 5.0 to 240,μg·mL-1 with the detection limit of 0.016μg·mL-1. Meanwhile the prepared sensor showed sensitive and selective binding sites for tolazoline. The enhancement of sensitivity was attributed to the presence of AuNPs which decreased the electron-transfer impedance.更多还原