Aptamer‐Functionalized Multidimensional Conducting‐Polymer Nanoparticles for an Ultrasensitive and Selective Field‐Effect‐Transistor Endocrine‐Disruptor Sensors

An endocrine disruptor (ED) is a type of xenobiotic compound that can cause serious diseases related to the estrous cycle, as well as various types of cancer. At low ED concentrations, estrogen receptors may respond as they would under physiological conditions. In this work, aptamer‐functionalized multidimensional conducting‐polymer (3‐carboxylate polypyrrole) nanoparticles (A_M_CPPyNPs) are fabricated for use in an FET sensor to detect bisphenol A (BPA). The multidimensional system, M_CPPyNPs, is first produced by means of dual‐nozzle electrospray of pristine CPPyNPs and vapor deposition polymerization of additional conducting polymer. The M_CPPyNPs are then immobilized on an amine‐functionalized (–NH₂) interdigitated‐array electrode substrate, through the formation of covalent bonds with amide groups (–CONH). The amine‐functionalized BPA‐binding aptamer is then introduced in the same way as that for M_CPPyNP immobilization. The resulting A_M_CPPyNP‐based FET sensors exhibit ultrasensitivity and selectivity towards BPA at unprecedentedly low concentrations (1 fm ) and among molecules with similar structures. Additionally, due to the covalent bonding involved in the immobilization processes, a longer lifetime is expected for the FET sensor.     

Novel Iron/Cobalt‐Containing Polypyrrole Hydrogel‐Derived Trifunctional Electrocatalyst for Self‐Powered Overall Water Splitting

Development of efficient, low‐cost, and durable electrocatalysts for the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) is of significant importance for many electrochemical devices, such as rechargeable metal–air batteries, fuel cells, and water electrolyzers. Here, a novel approach for the synthesis of a trifunctional electrocatalyst derived from iron/cobalt‐containing polypyrrole (PPy) hydrogel is reported. This strategy relies on the formation of a supramolecularly cross‐linked PPy hydrogel that allows for efficient and homogeneous incorporation of highly active Fe/Co–N–C species. Meanwhile, Co nanoparticles are also formed and embedded into the carbon scaffold during the pyrolysis process, further promoting electrochemical activities. The resultant electrocatalyst exhibits prominent catalytic activities for ORR, OER, and HER, surpassing previously reported trifunctional electrocatalysts. Finally, it is demonstrated that the as‐obtained trifunctional electrocatalyst can be used for electrocatalytic overall water splitting in a self‐powered manner under ambient conditions. This work offers new prospects in developing highly active, nonprecious‐metal‐based electrocatalysts in electrochemical energy devices.     

基于印迹聚吡咯膜电化学传感器检测S-卵白蛋白的研究

鉴于蛋清中S-卵白蛋白的含量与鸡蛋新鲜度和品质有较大相关性,将S-卵白蛋白含量作为评价鸡蛋新鲜度和品质的指标具有较大的前景和意义。本文通过循环伏安法和差分脉冲伏安法对传感器制备的扫描圈数、扫描速率、模板洗脱时间和孵化时间进行了优化,确定最佳扫描圈数为18,扫描速率为100 mV/s,模板洗脱时间为1.5 h,孵化时间为40 min,成功制备了能特异性识别S-卵白蛋白的印迹聚吡咯膜电化学传感器。采用场发射扫描电镜对印迹和非印迹传感器的微观结构进行了表征。通过差分脉冲伏安法,探讨了不同S-卵白蛋白浓度与峰电流变化的依赖关系,确定S-卵白蛋白浓度在10~(-6)～10~(-3) mg/mL范围内时,浓度与峰电流变化值具有良好线性关系,并得出检出限为6.75×10~(-7)mg/mL。该印迹传感器对S-卵白蛋白具有良好特异性性响应,可用于定量检测S-卵白蛋白。     

可拉伸聚吡咯/棉针织物的制备及其储电性能

为赋予棉针织物导电和储电的新功能并将其用于可穿戴器件中,将吡咯单体原位聚合到棉针织物上。借助扫描电子显微镜和红外光谱仪对棉针织物和聚吡咯的微观形貌以及化学结构进行表征,并测试了聚吡咯/棉针织物在不同拉伸应变时的表面电阻及电化学性能。结果表明:聚吡咯充分附着在针织棉纤维上;当拉伸应变从0%增至40%时,织物电阻值从429.2 Ω降至231.4 Ω;织物在5 mV/s条件下的储电面积容量为680.6 mF/cm ²,在2 mA/cm² 条件下为1 014.2 mF/cm²;由聚吡咯/棉针织物组装成的对称型超级电容器在1、5 mA/cm²时的面积容量分别为229.8、161.5 mF/cm²,经过10 000次恒流充放电循环后容量保留率为76.3%。     

高导电性铜/聚吡咯涂层羊毛织物的制备与表征

为研究等离子体处理时间对铜/聚吡咯/羊毛复合织物的导电性能,拓展羊毛织物在柔性传感器领域的应用,利用等离子体气相沉积技术对羊毛进行去鳞片化处理,依次对羊毛织物预处理300、600、900、1200 s,然后在羊毛织物表面原位聚合构建聚吡咯膜层,并用磁控溅射沉积铜薄膜增强纤维表面的导电网络;借助扫描电子显微镜、傅里叶红外...     

等离子体预处理对聚吡咯/涤纶经编导电织物结构和性能的影响

为改善导电高聚物在涤纶经编针织物上的附着效果,采用常温常压等离子体预处理方法对涤纶织物进行表面改性处理,并通过原位聚合法制备了聚吡咯/涤纶导电针织物,研究了等离子体预处理对聚吡咯在涤纶针织物上附着效果的影响,借助扫描电子显微镜和电阻仪分析了导电织物的微观形貌以及平磨前后方阻值的变化。结果表明:等离子体预处理方法可增加聚吡咯在涤纶上的附着量,改善聚吡咯在涤纶上的附着牢度,提高导电织物导电层在平磨过程中的保持程度,且附着量与等离子体预处理次数存在相关性:当等离子体预处理次数为4时,聚吡咯在涤纶针织物上的附着效果最佳。     

油酸和亚油酸在聚吡咯修饰铂电极上的电化学反应

基于醌的电化学还原原理,利用1,4-萘醌对游离脂肪酸的还原峰电流的测定,检测植物油中油酸和亚油酸的浓度,从而求出所测植物油的酸价。采用循环伏安法在乙腈溶液中聚合吡咯单体于铂电极表面制备化学修饰电极Ppy/ClO4-/Pt,用线性伏安法检测油酸和亚油酸浓度。结果表明:在浓度分别为5.3×10-3～7.9×10-2mol/L和9.6×10-6～1.28×10-3mol/L之间,还原峰电流与油酸和亚油酸浓度呈现良好的线性关系,相关系数(R2)分别是0.9948和0.9922,亚油酸和油酸的检出限为3.0×10-6mol/L和1.6×10-3mol/L(S/N=3)。并且将该化学修饰电极用于植物油橄榄油、玉米油、花生油、大豆油和芝麻油中酸价的检测,结果表明,化学修饰电极法是一种简便、快速实用的酸价滴定方法,可以作为碱滴定法的替代方法。     

The influence of dopant on the dielectric properties of flexible polypyrrole composites

Flexible polypyrrole composites with good dielectric properties were produced using pyrrole as a monomer by in situ polymerization on cotton fabric. The influence of the dopant type, and its concentration on the surface resistance of the composites, the real and imaginary parts of the dielectric constant, and the loss tangent were investigated. The results show that the type and concentration of dopant have a major influence on the surface resistance of the polypyrrole/cotton composite material, the real and imaginary parts of the dielectric constant, and the loss tangent. The polypyrrole/cotton composites show good performance in terms of their dielectric properties and conductivity, features which have laid the foundation for developing practical multipurpose absorbing composites.     

Core–shell polypyrrole nanoparticles obtained by atmospheric pressure plasma polymerization

Polypyrrole hollow nanoparticles were prepared by atmospheric pressure plasma polymerization. The structure of the nanoparticles was studied using Fourier transform infrared and X‐ray photoelectron spectroscopies, thermogravimetric analysis, scanning and transmission electron microscopies and atomic force microscopy. In contrast to low‐pressure plasma polymerization of pyrrole, which can produce films and solid nanoparticles, we obtained two types of hollow nanoparticles: a fraction with single spherical core and another with a core composed of small bubbles. Thermal characterization allowed us to determine that the nanoparticles are composed of highly crosslinked polymer. A mechanism that explains the formation of both types of hollow nanoparticles as well as solid nanoparticles is proposed. Chemical characterization shows that, in addition to the expected chemical structures due to pyrrole polymerization, the high energy of the plasma at atmospheric pressure produces intense dehydrogenation and oxidation processes. The fluorescence spectrum of the nanoparticles, however, shows a peak at 482 nm indicating that some degree of π‐conjugation is present in the material. © 2014 Society of Chemical Industry