Insights Into The Effect Of Nanoconfinement On Molecular Interactions And Its Application

As a unique phenomenon, confinement effect has attracted enormous attentions from physics to chemistry to material science. When a substance is confined in a nanoscale space, its physicochemical properties, such as density, miscibility, rigidity, reactivity, catalytic activity, and so on, may be dramatically different from those under non-confined conditions. Nanoconfinement effect often occurs in advanced materials such as nanomaterials, mesoporous materials, porous materials and nanopatterned surfaces. Thus, a comprehensive understanding of nanoconfinement effect can not only enable favorable properties but also facilitate rational design of advanced functional materials.Molecular interaction is the fundamental of multiple areas, such as sensing, separation, catalysis, drug delivery, and so on. In recent two decades, many advanced functional materials, which may involve in spatial confinement, have found increasing applications. For example, macroporous monoliths have been important media for chromatographic separations while functionalized mesoporous materials have been widely used as effective absorbents for sample pretreatment, and drug delievery. Besides, molecularly imprinted polymers (MIPs), whose specific binding with their targets relies on the 3D shape matching between nanoscale imprinted cavities and targets, have been practical substitutes for antibodies in many applications, while the nanopore of macroporous monolith has been utilized as a core element for the design of biomimetic materials. However, confinement effect on interactions associated with advanced functional materials has never been well studied. Although there are several related researches have been reported, understanding of molecular interactions under confined space has been still very limited.Herein we present for the first time a quantitative study on the effect of nanoscale confinement on molecular interactions using functionalized mesoporous silica as a host material. We show that both covalent and non-covalent interactions were enhanced by confinement and the enhancement depended on the closeness of the interacting location as well as the difference between the pore size and the molecular size. The more closed the interacting location, the larger the enhancement was; the smaller the difference, the larger the enhancement was. The overall enhancement could reach 3 orders of magnitude. These findings can not only provide new insights into molecular interactions under nanoconfinement but also facilitate rational design of functionalized materials for important applications, such as separation, drug delivery, sample preparation, and so on.Finally, since Chapter 2 revealed the connection between the nanoconfinement and molecular interactions. By untilizing the nanopore as a core element for design of the material. We design and synthesized mesoporous silica based molecular imprinting material by using adenosine monophosphate as the template. Because of the confinement effect provided both by mesopores from the material and nanopores from the imprinting site, the obtained material exhibits good selectivity and high affinity to the target molecules.