Size-selective separations of biological macromolecules on mesocylinder silica arrays

Abstract

In order to control the design functionality of mesocylinder filters for molecular sieving of proteins, we fabricated tight mesocylinder silica nanotube (NT) arrays as promising filter candidates for size-exclusion separation of high-concentration macromolecules, such as insulin (INS), α-amylase (AMY), β-lactoglobulin (β-LG), and myosin (MYO) proteins. In this study, hexagonal mesocylinder structures were fabricated successfully inside anodic alumina membrane (AAM) nanochannels using a variety of cationic and nonionic surfactants as templates. The systematic design of the nanofilters was based on densely patterned polar silane coupling agents (“linkers”) onto the AAM nanochannels, leading to the fabrication of mesocylinder silica arrays with vertical alignment and open surfaces of top-bottom ends inside AAM. Further surface coating of silica NTs hybrid AAM with hydrophobic agents facilitated the production of extremely robust constructed sequences of membranes without the formation of air gaps among NT arrays. The fabricated membranes with impermeable coated layers, robust surfaces, and uniformly multidirectional cylinder pores in nanoscale sizes rapidly separate large quantities of proteins within seconds. Meanwhile, comprehensive factors that affect the performance of the molecular transport, diffusivity, and filtration rate through nanofilter membranes were discussed. The mesocylinder filters of macromolecules show promise for the efficient separation and molecular transport of large molecular weight and size as well as concentrations of proteins.