Dendritic Mesoporous Silica Nanospheres: Toward the Ultimate Minimum Particle Size for Ultraefficient Liquid Chromatographic Separation

Abstract

Use of smaller particle size of packing materials in liquid chromatography leads to faster separation and higher efficiency. This basic law has driven the evolution of packing materials for several generations. However, the use of nanoscale packing materials has been severely hampered by extremely high back pressure. Here, we report a new possibility of solving this issue via introducing novel nanomaterials with highly favorable structures. n-Octyl-modified monodispersed dendritic mesoporous silica nanospheres (DMSNs) with an unprecedentedly small diameter (ca. 170 nm) and appropriate pore size (5.6 nm) were controllably synthesized and demonstrated to be a practically applicable packing material offering ultrahigh efficiency. The center-radial centrosymmetric mesopore channels significantly improved the permeability of packed capillaries, enabling column packing and capillary electrochromatographic separation on regular instruments. Due to the unique morphology, very tiny particle size, and highly uniform packing, the packed column exhibited ultrahigh efficiency up to 3 500 000 plates/m. Powerful separation capability was demonstrated with glycan profiling of cancerous and normal cells, which revealed that cancerous cells exhibited characteristic N-glycans. Because DMSNs with tunable particle size and mesopores can be controllably prepared, DMSNs hold great potential to be a new record toward the ultimate generation of packing materials for ultraefficient liquid chromatographic separation.

Magnetic Dendritic Polymer Nanospheres for High-Performance Separation of Histidine-Rich Proteins

“…Simultaneously, SEM Figure e reveals a pore size with tens of nanometers at the outer surface of the templates. Since wide radial pore channels exist, the inner surface of the silica spheres seems accessible for loading nanoparticle guests . After in situ surface precipitation of iron oxides in the presence of dSiO 2 nanospheres, the TEM and SEM (Figure b,f) images of the resulting dSiO 2 @Fe 3 O 4 nanospheres show the high pyrolysis and homogeneous distribution of Fe 3 O 4 nanoparticles (brighter spots compared with the surrounding silica matrix) throughout the whole nanospheres.…”

“…Since wide radial pore channels exist, the inner surface of the silica spheres seems accessible for loading nanoparticle guests. 41 After in situ surface precipitation of iron oxides in the presence of dSiO 2 nanospheres, the TEM and SEM (Figure 1b,f) images of the resulting dSiO 2 @Fe 3 O 4 nanospheres show the high pyrolysis and homogeneous distribution of Fe 3 O 4 nanoparticles (brighter spots compared with the surrounding silica matrix) throughout the whole nanospheres. On this basis, the surface of dSiO 2 @Fe 3 O 4 was modified with TA through the strong adsorption between carboxylic acid groups and metal atoms, resulting in a thinner layer on the surface with an average diameter of (2 ± 0.3) nm (Figure 1c,g).…”

Chromatographic separation of peptides and proteins for characterization of proteomes

“…31 Recently, Liu et al packed 170 nm dendritic mesoporous silica nanospheres into the capillary for electrochromatography separation. 32 The center-radial centrosymmetric mesopore channels significantly improved the permeability of packed capillaries, enabling column packing and capillary electrochromatographic separation. The practical application of the submicrometer particles into the separation of complex samples might be on the way.…”

Single-Crystalline Covalent Organic Frameworks as High-Performance Liquid Chromatographic Stationary Phases for Positional Isomer Separation

“…Chromatography has gained substantial attention due to its powerful separation ability, precise qualitative or quantitative analysis, and good reproducibility. − As the key point to realize isomeric separation in chromatography, the exploitation of stationary phases is of great importance. In recent years, diverse porous materials have been investigated as advanced stationary phases for positional isomer separation, such as metal–organic cages, , metal–organic frameworks (MOFs), microporous organic polymers, and microporous organic networks .…”