Layer-by-Layer Surface Molecular Imprinting on Polyacrylonitrile Nanofiber Mats

Abstract

Surface molecular imprinting in layer-by-layer (SMI-LbL) film is known as a facile and effective strategy to build imprinting sites that are more accessible to template molecules compared with molecular imprinting in polymers. Herein, we accomplished the formation of SMI-LbL film on electrospun nanofibers for the first time. The SMI-LbL nanofibers were prepared by a template-induced LbL process on the polyacrylonitrile (PAN) nanofiber substrates, followed by postinfiltrating and photo-cross-linking of photosensitive agent 4,4'-diazostilbene-2,2'-disulfonic acid disodium salt (DAS). The obtained nanofiber mat maintained the nanofibrous structure and showed rapid absorption and extraction of template molecules of meso-tetra(4-carboxyphenyl)-porphine (Por). The binding capacity of Por reached 2.1 mg/g when 3.5 bilayers were deposited on the nanofibers. After six cycles of extraction and reabsorption, the binding capacity of Por remained at 83%. Moreover, the absorption results of the targeted templated molecule of Por and the control molecule of Fast Green, which had a very similar chemical structure and charge status to Por, indicated the specific absorption for template molecule of Por. Thus, a surface molecular imprinted nanofiber mat with high selectivity of the templated molecule has been demonstrated.

Long-period grating fiber-optic sensors exploiting molecularly imprinted TiO2 nanothin films with photocatalytic self-cleaning ability

“…In particular, molecularly imprinted thin films have many advantages, including a quick response time and high sensitivity and selectivity [6]. Different methodologies have been employed for the preparation of molecularly imprinted films, such as organically modified sol-gel methods [7], the layer-by-layer (LbL) technique [8], liquid phase deposition (LPD) [9], and spin coating [10]. Silica gel [11] and organic polymers [12] can also be used for the fabrication of molecularly imprinted films, in which templates can be embedded via cross-linking of matrix monomers.…”

Synthesis and Characterization of a Molecularly Imprinted Polymer of Spermidine and the Exploration of Its Molecular Recognition Properties

“…The recognition ability depends on the presence of covalent/non-covalent bond interactions and the special geometrical shape of the cavity [10]. Molecularly imprinted polymers (MIPs) are resistant to mechanical, acid, and alkali damage, and have therefore been widely used in high value-added substance enrichment [11], chemical processes [12], biosensing [13,14], surface functional coatings [15], and environmental detection [16,17]. MIPs can be prepared by covalent (pre-assembly method) and non-covalent (self-assembly method) methods, which involve different ways of combining template molecules and functional monomers.…”

Synthesis of a surface molecular imprinting polymer based on silica and its application in the identification of nitrocellulose

“…This results from the fact that the three-dimensional cavities in the synthesized MIP are not easily accessible to template molecules, thus leading to a poor binding capacity, slow binding kinetics and difficult template removal. To improve the traditional MIT, alternative approaches have been explored such as surface molecular imprinting, 26,27 magnetic molecular imprinting, 28,29 core-shell polymerization 30 etc. Surface molecularly imprinted technology (SMIT) has been applied extensively, because the generated cavities are located on the surface of the materials, which decreases the resistance to mass transfer thus facilitating the contact of the template molecules with recognition sites in the polymer matrix.…”