Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering , Jiangnan University , Wuxi 214122 , Jiangsu Province , P. R. China.
ACS Appl Mater Interfaces. 2018 Jul 25;10(29):24850-24859. doi: 10.1021/acsami.8b08558. Epub 2018 Jul 13.
In this study, molecularly imprinted nanohybrids with "necklace-like" nanostructures were developed based on self-assembled polymeric nanoparticles decorated multiwalled carbon nanotubes (MWCNTs) by employing melamine as template molecules. An amphiphilic copolymer poly(acrylic acid- co-(7-(4-vinylbenzyloxy)-4-methyl coumarin)- co-ethylhexyl acrylate) (poly(AA- co-VMc- co-EHA), PAVE) containing photosensitive coumarin units was synthesized first. Then, the PAVE copolymers were co-assembled with MWCNTs in the presence of template molecules, generating photosensitive molecularly imprinted nanohybrids (MIP-MWCNTs) with necklace-like structures. Subsequently, the MIP-MWCNTs nanohybrids were used to modify electrode surface followed by photo-polymerization of the coumarin units in the nanohybrids, leading to a network architectured complex film. After extracting melamine molecules by electrolysis, a melamine MIP sensor was successfully developed. The as-prepared sensor exhibited a significantly wide linear range (1.0 × 10-1.0 × 10 mol L) and a low detection limit (5.6 × 10 mol L) for melamine detection. High selectivity of the sensor toward melamine was well demonstrated with respect to other melamine analogues and interferents. Furthermore, the MIP sensor showed high stability and reproducibility. The excellent performance of the MIP sensor can be attributed to the unique nanostructure of the complex film provided by these necklace-like nanohybrids. On the one hand, the nanosized polymeric MIP nanoparticles along the MWCNTs increase the effective electrode surface area and thus offer a high melamine-binding capacity. On the other hand, the MWCNTs in MIP-MWCNTs nanohybrids serve as "electronic bridges" to accelerate the electron transfer among the complex MIP film. More importantly, the MIP sensor was practically used to monitor melamine in milk samples, demonstrating a promising feature for applications in the analysis of food like milk and other food products including milk powder, infant formula, and animal feed. Considering the ease of polymeric nanoparticles functionalization, the necklace-like nanohybrids would be extended to wider applications in many other sensors and devices.
在这项研究中，基于自组装的聚合物纳米粒子修饰的多壁碳纳米管（MWCNTs），通过使用三聚氰胺作为模板分子，开发了具有“项链状”纳米结构的分子印迹纳米杂化物。首先合成了含有光敏香豆素单元的两亲性共聚物聚（丙烯酸-co-（7-（4-乙烯基苄氧基）-4-甲基香豆素）-co-乙基己基丙烯酸酯）（poly（AA-co-VMc-co-EHA），PAVE）。然后，在模板分子存在下，将 PAVE 共聚物与 MWCNTs 共聚组装，生成具有项链状结构的光敏分子印迹纳米杂化物（MIP-MWCNTs）。随后，将 MIP-MWCNTs 纳米杂化物用于修饰电极表面，然后在纳米杂化物中光聚合香豆素单元，得到具有网络结构的复合膜。通过电解提取三聚氰胺分子后，成功制备了三聚氰胺分子印迹传感器。所制备的传感器对三聚氰胺的检测表现出非常宽的线性范围（1.0×10-1.0×10 mol L）和低检测限（5.6×10 mol L）。与其他三聚氰胺类似物和干扰物相比，该传感器对三聚氰胺具有良好的选择性。此外，该传感器表现出较高的稳定性和重现性。该分子印迹传感器的优异性能归因于这些项链状纳米杂化物提供的独特复合膜的纳米结构。一方面，MWCNTs 上沿的纳米尺寸聚合物 MIP 纳米颗粒增加了有效电极表面积，从而提供了高的三聚氰胺结合能力。另一方面，MWCNTs 在 MIP-MWCNTs 纳米杂化物中作为“电子桥”，加速了复合 MIP 膜中的电子转移。更重要的是，该分子印迹传感器实际用于监测牛奶样品中的三聚氰胺，为在分析牛奶等食品以及包括奶粉、婴儿配方奶粉和动物饲料在内的其他食品产品中的三聚氰胺的应用提供了广阔的前景。考虑到聚合物纳米颗粒的功能化容易，项链状纳米杂化物将扩展到更广泛的其他传感器和设备的应用中。
