表面印迹聚合物萃取/气相色谱质谱联用检测双酚A

以双酚A(BPA)为模板分子,甲基丙烯酸为单体,乙二醇二甲基丙烯酸酯作为交联剂,在硅胶表面合成双酚A分子印迹聚合物。通过红外光谱、比表面积测定等对表面印迹聚合物进行分析和表征;采用静态吸附法和动态吸附法对其吸附性能进行考察。红外光谱表明硅胶表面生成了对模板分子具有识别功能的官能团;热重分析证明该印迹聚合物具有良好的热稳定性;静态吸附实验说明表面印迹聚合物比非印迹聚合物具有良好的吸附性能,该印迹聚合物对双酚A最大吸附容量Q max为1.501 mg/g,吸附速率常数k为0.01586g/(mg·min)。用表面印迹聚合物萃取(MISPE)和气相色谱质谱(GC-MS)联用检测了BPA样品,BPA的回收率接近90%,并将该双酚A表面印迹聚合物用于牛奶样品中的BPA测试,结果表明该印迹聚合物具有较好的吸附选择性。     

基于纳米金增敏的双酚A二氧化钛凝胶分子印迹电化学传感器的制备及应用

以纳米金(Au NPs)为增敏材料,双酚A(BPA)为模板分子,结合表面溶胶凝胶法和自组装法,制备了BPA纳米金-Ti O_2凝胶分子印迹电化学传感器。利用扫描电子显微镜和能谱对Au NPs进行了表征,利用红外光谱仪对Ti O_2凝胶、BPA以及BPA印迹Ti O_2凝胶进行表征。在最优条件下,该传感器对BPA在1.0×10~(-8)~1.0×10~(-5)mol/L浓度范围内具有良好的线性关系,线性相关系数为0.995,检测限为0.6×10~(-8)mol/L,并将该分子印迹传感器应用于实际样品中BPA的分析检测,其回收率为97.4%~103%。     

含模板结构分子印迹材料制备及识别性能研究

以双酚A(BPA)为模板分子,α-甲基丙烯酸(MAA)为功能单体,以含模板分子结构的双酚A二甲基丙烯酸酯(BPDMA)为交联剂,制备了含模板结构的分子印迹聚合物材料,并与以二甲基丙烯酸乙二醇酯(EGDMA)和N, N-亚甲基双丙烯酰胺(BIS)为交联剂制备的BPA印迹材料进行对比。结果表明:以BPDMA为交联剂制备的材料印迹性能最佳,其印迹因子为5.32,吸附量为5.05 mg/g;以EGDMA和BIS为交联剂制备的材料印迹因子分别为1.41和1.45,吸附容量分别为0.96 mg/g和2.79 mg/g。将所制备材料应用于牛奶中BPA的富集检测,得到的加标回收率为95.0%～98.9%,相对标准偏差为3.5%～4.2%,表明得到的印迹材料可用于复杂体系BPA的选择性富集。     

聚氨基苯酚分子印迹电化学传感器测定双酚A

该工作通过电化学方法在多壁碳纳米管修饰的玻碳电极表面得到聚邻氨基苯酚分子印迹聚合物膜,制备了可以选择性识别双酚A的分子印迹电化学传感器。通过扫描电镜、循环伏安法以及差分脉冲法对传感器的表面形貌和电化学性能进行了表征,并对传感器的检测条件进行了优化。采用K_3[Fe(CN)_6]作为电化学探针,在选定的实验条件下,K_3[Fe(CN)_6]在印迹电极上的峰电流变化值与双酚A的浓度在1×10~(-10)-4×10~(-8) mol·L~(-1)呈良好线性,本方法测定双酚A的检测限为4×1 0 ~(-11) mol·L~(-1),将该传感器用于实际水样中双酚A的测定,结果令人满意。     

分子印迹磁性固相萃取/液相色谱法检测奶制品中的双酚A

以双酚A(BPA)为模板分子,磁性二氧化硅(Fe_3O_4@SiO_2)为载体,4-乙烯基吡啶(4-VP)为功能单体,采用表面分子印迹技术制备了双酚A磁性分子印迹聚合物微球(Fe_3O_4@SiO_2-MIPs)。通过红外光谱、透射电镜等对Fe_3O_4@SiO_2-MIPs进行了结构和形貌的表征。将制得的Fe_3O_4@SiO_2-MIPs作为磁性吸附剂,分离富集奶制品中的BPA,建立了分子印迹磁性固相萃取/液相色谱法测定奶制品中BPA的新方法。结果表明,在优化条件下,Fe_3O_4@SiO_2-MIPs对BPA具有良好的选择性,最大吸附容量达13.50 mg/g,在0.05~5.0 mmol/L浓度范围内有良好的线性关系(r2=0.993 4),方法检出限为0.037μg/L,样品加标回收率为86.2%~93.1%,相对标准偏差为2.9%~3.8%。该方法高效快速,选择性好,可用于牛奶样品中痕量BPA的检测。     

基于双功能单体的磁性双酚A印迹聚合物的制备及应用

以二氧化硅包覆的四氧化三铁为载体,双酚A(BPA)为模板分子,β-环糊精和4-乙烯基吡啶为二元功能单体,采用热聚合方法制备了对双酚A具有特异吸附性能的磁性印迹复合材料(mag-MIPs).采用透射电子显微镜(TEM)、傅里叶变换红外光谱(FTIR)和振动样品磁强计(VSM)对该印迹复合材料进行了表征,并结合磁固相萃取(M-SPE)技术和高效液相色谱(HPLC)研究了其对双酚A的吸附行为,结果表明该印迹复合材料对双酚A具有良好的选择吸附能力.液相色谱检测结果表明,该磁性印迹复合材料可用于环境水样中双酚A的快速分离富集,回收率为90.51%~98.21%.     

双酚A分子印迹固相微萃取头的快速制备（英文）

以双酚A(BPA)为模板分子,乙腈(ACN)为致孔剂,α-甲基丙烯酸为功能单体(MAA),乙二醇二甲基丙烯酸酯(EDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂,快速制备了双酚A分子印迹聚合物(MIP)萃取头。聚合反应在内径为530μm的毛细管中进行,微波聚合7 min。得到的双酚A分子印迹聚合物从毛细管中推出,在安培瓶中洗脱后再次插入毛细管中用于固相微萃取(SPME)。在不同的模板分子和功能单体的比例(BPA/MAA)、NaCl浓度、萃取和解吸时间、pH值和解吸溶剂条件下考察了聚合物的萃取性能。选取结构类似物苯酚(P)、对羟基联苯(PP)和非结构类似物二聚氰胺(DCD),对MIP和非印迹聚合物(NIP)的选择性吸附性能进行了对比。所建立的SPME方法结合高效液相色谱法(HPLC)成功用于饮料中双酚A的检测。在优化的实验条件下,双酚A的线性范围为10~400μg/L,检出限(LOD)为0.45μg/L,在矿泉水中的回收率为88.4%~102.8%。结果表明所建立的方法能够用于检测实际样品中的BPA,具有样品预处理简便、分析快速、检出限低和消耗低的优点。     

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6.0×10-7～5.5×10-5 mol/L浓度范围内峰电流值与浓度呈良好线性关系(r=0.991);检出限2.0×10-7 mol/L; 相对标准偏差<5%(n=9),达到稳定电流所用时间约2 min.此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.     

磁性双酚A分子印迹材料的制备及性能研究

采用沉淀法制备了Fe_3O_4磁性微球,以硅烷化试剂对其表面改性后作为载体,以双酚A为模板分子,甲基丙烯酸为功能单体,N,N′-亚甲基双丙烯酰胺为交联剂,采用乳液聚合法制备了对BPA有特异吸附性能的磁性分子印迹材料(MMIPs)。此材料具有较强的磁性和对双酚A的吸附性,可以在外加磁场的条件下方便实现水中双酚A的富集分离。溶液中双酚A的质量浓度为60mg·L~(-1)时,制备的磁性MIPs材料对双酚A饱和吸附量为22.06mg·g~(-1),60min达到吸附平衡。     

白藜芦醇分子印迹复合膜的制备及其选择性能

以反式白藜芦醇为模板分子,聚偏氟乙烯微孔滤膜为支撑膜,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸脂(EDMA)为交联剂,采用热引发原位聚合方法制备了白藜芦醇分子印迹聚合物膜。研究了分子印迹膜对白藜芦醇及其结构类似物(2-萘酚、白藜芦醇甙和双酚A)的结合和透过性,并用扫描电镜对膜形貌进行了表征。结果表明,印迹复合膜对模板分子白藜芦醇具有良好的吸附选择性,印迹膜对白藜芦醇的吸附量远远大于其它结构类似物,其饱和吸附量达1.72μmol/g,为非印迹膜的3倍;尺寸效应和印迹效应是影响物质在印迹膜上的透过量的两个重要因素,尺寸比模板分子小的2-萘酚最先透过,而相对于尺寸接近或大于模板分子的双酚A或白藜芦醇甙,模板分子优先透过。而且,模板分子在印迹膜上的透过量大于非印迹膜。     

A microvolume molecularly imprinted polymer modified fiber-optic evanescent wave sensor for bisphenol A determination

A fiber-optic evanescent wave sensor for bisphenol A (BPA) determination based on a molecularly imprinted polymer (MIP)-modified fiber column was developed. MIP film immobilized with BPA was synthesized on the fiber column, and the sensor was then constructed by inserting the optical fiber prepared into a transparent capillary. A microchannel (about 2.0 μL) formed between the fiber and the capillary acted as a flow cell. BPA can be selectively adsorbed online by the MIP film and excited to produce fluorescence by the evanescent wave produced on the fiber core surface. The conditions for BPA enrichment, elution, and fluorescence detection are discussed in detail. The analytical measurements were made at 276 nm/306 nm (λ _ex/λ _em), and linearity of 3?×?10^?9–5?×?10^?6 g mL^?1 BPA, a limit of detection of 1.7?×?10^?9 g mL^?1 BPA (3σ), and a relative standard deviation of 2.4 % (n?=?5) were obtained. The sensor selectivity and MIP binding measurement were also evaluated. The results indicated that the selectivity and sensitivity of the proposed fiber-optic sensor could be greatly improved by using MIP as a recognition and enrichment element. Further, by modification of the sensing and detection elements on the optical fiber, the proposed sensor showed the advantages of easy fabrication and low cost. The novel sensor configuration provided a platform for monitoring other species by simply changing the light source and sensing elements. The sensor presented has been successfully applied to determine BPA released from plastic products treated at different temperatures.

Electrochemical sensors based on molecularly imprinted polymers grafted onto gold electrodes using click chemistry

We have developed a three-step method to graft molecularly imprinted polymer (MIP) thin films onto Au electrodes. In the first step, propargyl acrylate is clicked onto an azidoundecanethiol (N(3)(CH(2))(11)SH)/decanethiol mixed self-assembled monolayer (SAM). Then, by applying UV light (365 nm) in the presence of N,N'-methylenebis(acrylamide) (MAAM) and azobisisobutyronitrile (AIBN) as the radical initiator, polymerization was carried out directly on the electrode surface in the presence of an electroactive template molecule, hydroquinone (HQ). Detection of HQ using the clicked-on MIP sensor was studied using chronoamperometry and its behavior was compared to that of a sensor prepared by drop-coating MIPs onto Au. The detection limit of the clicked-on MIP sensor for HQ was found to be 1.21±0.56 μM, about four times lower than what was observed using the coated-on MIP sensor. In addition, the sensitivity of the clicked-on MIP sensor was found to be approximately three times greater than the coated-on MIP sensor. Apparent diffusion coefficients determined using chronoamperometry suggest that the improved performance is likely due to the favorable mass transfer characteristics of the clicked-on MIP sensing membrane.     

基于分子印迹技术的牛血清白蛋白电位式传感器的研究

以牛血清白蛋白(BSA)为模板,合成了分子印迹聚合物凝胶(MIP),进而制得了以聚氯乙烯(PVC)为支撑膜的BSA电位式传感器。采用直接电位法测得BSA在浓度0.1～1.0 mg/mL范围内与电位呈线性关系。此电极制作简单,可用于BSA的测定。     

Hydrophilic molecularly imprinted polymers for bisphenol A prepared in aqueous solution

We have prepared a hydrophilic molecularly imprinted polymer (MIP) for the hydrophobic compound bisphenol A (BPA) in aqueous solution using 3-acrylamido-N,N,N-trimethylpropan-1-aminium chloride (AMTC) as the functional monomer. Under redox-polymerization conditions, BPA forms an ion-pair with AMTC, which was confirmed by ¹H-NMR titration. The imprinting effect in aqueous solution was evaluated by comparison of this material with the corresponding non-imprinted polymer (NIP) and with a control polymer (CP) bearing no AMTC. The MIP showed the highest activity among the three polymers, and the imprinting factors as calculated from the amount of BPA bound to the MIP divided by the amounts bound to NIP and CP, respectively, are 1.8 and 6.0. The MIP was selective for BPA in aqueous solution, while structurally related compounds are not recognized. Such a selectivity for a hydrophobic compound is rarely observed in aqueous medium because non-specific binding of BPA inevitably leads to hydrophobic interaction.

Molecularly imprinted polymers for bisphenol A for HPLC and SPE from water and milk

Molecularly imprinted polymers (MIPs) for bisphenol A (BPA) were prepared by two synthetic routes: semi-covalent and noncovalent methodology. The molecular imprinting effect was evaluated using the polymers in HPLC and SPE. Polymers prepared with noncovalent mode were proven more effective. These polymers were applied in SPE facilitating selective retention of BPA from bottled water and milk. The developed sample preparation was simple and efficient comprising only dilution of milk and MISPE prior to LC-MS analysis. Overall MISPE enhanced sample clean-up. Compared with control nonimprinted polymers and conventional C18 SPE cartridges, the MIPs exhibited selective analyte recognition. The method provided quantitative BPA recoveries, very good reproducibility (% RSDs lower than 7%), and low LOD (0.2 ng/g). MIP interacts similarly with deuterated BPA allowing its use as internal standard in LC-MS. The most critical parameters of MISPE were the organic content in loading-washing medium and the washing volume. Low flow rates in the elution step enhanced extraction recovery. Important advantages of the MIP were: the high breakthrough volumes (> 500 mL of water), high mass capacity (> 10 ng/mg of MIP sorbent), good linearity, and good stability in performance for over 35 cycles of use.     

Molecularly Imprinted Polyresorcinol Based Capacitive Sensor for Sulphanilamide Detection

A molecularly imprinted polymer (MIP) based capacitive sensor for antibiotic detection in drinking water and milk has been developed on a gold coated silicon electrode (Au Electrode). The electrode was fabricated by electropolymerizing monomer resorcinol (RN) on Au surface in presence of sulphanilamide (SN) as a template molecule, to get insulated RN polymer antibiotic composite. The insulation of the polymer film was improved by incubation of electrode in 1‐Dodecanethiol solution. Subsequently MIP sensor was obtained by extraction of SN in ethanol and acetic acid solution. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) measurements were performed for characterization of the developed MIP electrode at different steps of fabrication. The surface morphology of MIP electrode was characterized using atomic force microscopy (AFM), X‐ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive x‐ray spectroscopy (EDS). Performance of MIP sensor was evaluated by measuring change in capacitance against varying concentration of SN using EIS. A linear response in the range 1 to 200 μg L^?1 SN was recorded for MIP sensor with a detection limit of 0.1 μg L^?1. The developed MIP sensor exhibited good selectivity towards SN in water and milk with recoveries in the range 92 % to 105 %. The obtained results suggest the usability of MIP based sensor for SN estimation in water and milk samples.     

分子印迹聚合物修饰电化学晶体管检测抗坏血酸分子

以抗坏血酸(AA)为模板分子、邻苯二胺(o-PD)为功能单体,在金电极表面电聚合制备分子印迹聚合物膜(MIP),并以该MIP修饰的电极为栅极制备了具有高选择性、高灵敏度的AA电化学晶体管(OECT)传感器件。应用循环伏安法(CV)、交流阻抗法(EIS)对分子印迹聚合物电极进行一系列的表征与检测。实验结果表明:以pH=5.2,浓度为0.2mol/L HAc-NaAc(体积比2.1∶7.9)的缓冲液为背景溶液,o-PD与AA的物质的量之比为1∶2,以0.5V/s的扫描速率在0~0.8V内扫描20圈,所得分子印迹膜电极性能最佳。应用以该分子印迹修饰电极作为栅极的电化学晶体管检测AA,得到AA浓度的检测限为0.3μmol/L,沟道电流与AA浓度在0.3~3μmol/L(低浓度)与3~100μmol/L(高浓度)这2个范围内成线性关系。     

Preparation and evaluation of molecularly imprinted solid-phase microextraction fibers for selective extraction of bisphenol A in complex samples

Molecular imprinted polymer (MIP) as solid-phase microextraction (SPME) fibers coating has gained great attention in recent years. In this study, a simple preparation approach for bisphenol A (BPA) MIP coating with controlled thickness on fused-silica capillaries was developed. A capillary was inserted into a larger bore capillary to form a sleeve as mold. The prepolymer solution containing the template BPA was introduced into the interspace between the two capillaries for polymerization under photoirradiation. The larger bore capillary was removed away after the polymerization, and MIP coating with certain thickness on the surface of the inserted capillary was obtained. SPME conditions based on the MIP-coated fibers were optimized, and the extraction performance of the fibers with different thickness coating was compared. Finally, the MIP fibers were used for selective extraction of BPA spiked in tap water, human urine, and milk samples. The average recoveries of spiked BPA in the three samples were 92.5%, 81.6%, and 87.5%, respectively. The present analytical performance is not up to par for applicability to real environmental matrices. Further improvement will be necessary for analysis of real complex samples.     

Competitive CE-UV binding tests for selective recognition of bisphenol A by molecularly imprinted polymer particles

Capillary electrophoresis with ultraviolet detection (CE-UV) was used to perform competitive binding tests to demonstrate the selective recognition of bisphenol A (BPA) by molecularly imprinted polymer (MIP) particles. Cross-linking polymerization of methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) in the presence of BPA yielded MIP particles with an average diameter of 164 ± 15 nm. Their ability to recognize BPA in the presence of nonionic, anionic, and cationic water contaminants was investigated. Binding efficiency was rapidly determined, after sequential injection of particles first and compounds next into the fused-silica capillary provided a short overlapping time during their electrophoretic migrations. The MIP particles exhibited high-binding efficiency (99 ± 1%) for BPA. Neither diclofenac nor metformin affected BPA binding, and 2-hydroxy-4-methoxybenzophenone was even displaced from the particles by BPA. These results verified the high selectivity of MIP toward its target compound.