Synthesis of a novel restricted access chiral stationary phase based on atom transfer radical polymerization and click chemistry for the analysis of chiral drugs in biological matrices

Contribution of the "Click Chemistry" Toolbox for the Design, Synthesis, and Resulting Applications of Innovative and Efficient Separative Supports: Time for Assessment

The last two decades have seen the rapid expansion of click chemistry methodology in various domains closely related to organic chemistry. It has notably been widely developed in the area of surface chemistry, mainly because of the high-yielding character of reactions of the "click" type. Especially, this powerful chemical reaction toolbox has been adapted to the preparation of stationary phases from the corresponding chromatographic supports. A plethora of selectors can thus be immobilized on either organic, inorganic, or hybrid stationary phases that can be used in different chromatographic modes. This review first highlights the few different chemical ligation strategies of the "click" type that are up to now mainly devoted to the development of functionalized supports for separation sciences. Then, it gives in a second part an up-to-date survey of the different studies dedicated to the preparation of click chemistry-based chromatographic supports while highlighting the powerful and versatile character of the "click" ligation strategy for the design, synthesis, and developments of more and more complex systems that can find promising applications in the area of analytical sciences, in domains as varied as enantioselective separation, glycomics, proteomics, genomics, metabolomics, etc.

Functional materials generated by allying cyclodextrin-based supramolecular chemistry with living polymerization

Cyclodextrin molecules are cyclic oligosaccharides that display a unique structure including an inner side and two faces on their outer sides.

Preparation of a monolithic cation-exchange material with hydrophilic external layers by two-step reversible addition-fragmentation chain transfer polymerization

In recent years, the efficient analysis of biological samples has become more important due to the advances of life science and pharmaceutical research and practice. Because biological sample pretreatment is the bottleneck for fast process, material development for efficient sample process in the high-performance liquid chromatography analysis is highly desirable. In this research, a cation-exchange restricted access monolithic column was synthesized by a reversible addition-fragmentation chain transfer polymerization method. Utilizing the controlled/living property of the reversible addition-fragmentation chain transfer method, a monolithic column of cross-linked poly(sulfopropyl methacrylate) was prepared first and then linear poly(glycerol mono-methacrylate) was immobilized covalently on the surface of the polymer. The monolithic material has both functionalities of cation-exchange and protein exclusion. Protein recovery of 94.6% was obtained after grafting of poly(glycerol mono-methacrylate) while the cation-exchange property of the column is still retained. In the study, the relation between the synthetic conditions and properties of the materials was studied. The synthesis conditions including the porogen, monomer concentration, and ratio of monomers/initiator/reversible addition-fragmentation chain transfer agent were optimized. The study provided a method for the preparation of restricted access monolithic columns: a bifunctional material by reversible addition-fragmentation chain transfer polymerization method.

Surface-Initiated Controlled Radical Polymerization: State-of-the-Art, Opportunities, and Challenges in Surface and Interface Engineering with Polymer Brushes

The generation of polymer brushes by surface-initiated controlled radical polymerization (SI-CRP) techniques has become a powerful approach to tailor the chemical and physical properties of interfaces and has given rise to great advances in surface and interface engineering. Polymer brushes are defined as thin polymer films in which the individual polymer chains are tethered by one chain end to a solid interface. Significant advances have been made over the past years in the field of polymer brushes. This includes novel developments in SI-CRP, as well as the emergence of novel applications such as catalysis, electronics, nanomaterial synthesis and biosensing. Additionally, polymer brushes prepared via SI-CRP have been utilized to modify the surface of novel substrates such as natural fibers, polymer nanofibers, mesoporous materials, graphene, viruses and protein nanoparticles. The last years have also seen exciting advances in the chemical and physical characterization of polymer brushes, as well as an ever increasing set of computational and simulation tools that allow understanding and predictions of these surface-grafted polymer architectures. The aim of this contribution is to provide a comprehensive review that critically assesses recent advances in the field and highlights the opportunities and challenges for future work.

Functional Interfaces Constructed by Controlled/Living Radical Polymerization for Analytical Chemistry

The high-value applications of functional polymers in analytical science generally require well-defined interfaces, including precisely synthesized molecular architectures and compositions. Controlled/living radical polymerization (CRP) has been developed as a versatile and powerful tool for the preparation of polymers with narrow molecular weight distributions and predetermined molecular weights. Among the CRP system, atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) are well-used to develop new materials for analytical science, such as surface-modified core-shell particles, monoliths, MIP micro- or nanospheres, fluorescent nanoparticles, and multifunctional materials. In this review, we summarize the emerging functional interfaces constructed by RAFT and ATRP for applications in analytical science. Various polymers with precisely controlled architectures including homopolymers, block copolymers, molecular imprinted copolymers, and grafted copolymers were synthesized by CRP methods for molecular separation, retention, or sensing. We expect that the CRP methods will become the most popular technique for preparing functional polymers that can be broadly applied in analytical chemistry.

Emerging enantiomeric resolution materials with homochiral nano-fabrications

The major scientific challenge of enantiomeric separation is to develop simple, rapid, and sensitive routine analytical methods. Generally, enantio-resolution is still based on "three-point interaction" theory, which indicates that homochiral sites are needed for enantio-selective interaction. However, in recent years, advanced materials with precise homochiral fabrication at the nanoscale have been synthesized, and have shown great potential in development of high-throughput enantio-resolution methods. This tutorial review summarizes fabrication and applications of homochiral materials for enantio-selective recognition and separation. These materials, which include intrinsic and restructured chiral metal surfaces, plasmonic nanostructures, coordination polymers, organic polymer sensors, and molecularly imprinted polymers, have been applied as sensors or chiral stationary phases (CSPs) for efficient enantio-resolution.