Patterned Poly(2-hydroxyethyl methacrylate) Brushes on Silicon Surfaces Behave as “Tentacles” To Capture Ferritin from Aqueous Solution

Abstract

We have used a very large scale integration process to generate well-defined patterns of polymerized 2-hydroxyethyl methacrylate (HEMA) on patterned Si(100) surfaces. An atom transfer radical polymerization initiator covalently bonded to the patterned surface was employed for the graft polymerization of HEMA to prepare the poly(2-hydroxyethyl methacrylate) (PHEMA) brushes. After immersing wafers presenting lines of these polymers in water and cyclohexane, we observed brush- and mushroom-like regions, respectively, for the PHEMA brushes, with various pattern resolutions. The PHEMA brushes behaved as "tentacles" that captured ferritin complexes from aqueous solution through entanglement between the brushes and the ferritin proteins, whose ferritins were trapped due to the collapsing of the PHEMA. Using high-resolution scanning electron microscopy, we observed patterned ferritin iron cores on the Si surface after thermal removal of the patterned PHEMA brushes and ferritin protein sheaths.

Synthesis of doubly functional nanowhiskers from a colloid solution including a V–Ti complex precursor

“…These were curve fitted using peaks with binding energies of 284.2, 285.8, and 287.6 eV, attributable to chemical bonding environments C-C/H, C-N, and C=O of PVP, respectively. [22][23][24][25] For the precursor that had been treated at 700°C, a signal appeared at a binding energy of 285.4 eV. This value is inconsistent with the binding energy of a V-C bond (282.5 eV) [26], but is quite close to that reported for C-O bonds in superfical carbon-doped TiO 2 samples [27].…”

Fabrication of high-aspect-ratio poly(2-hydroxyethyl methacrylate) brushes patterned on silica surfaces by very-large-scale integration process

“…The heights for patterned single lines of PHEMA brushes grafted for 24 h from trenches having resolutions of 350 and 1500 nm were 96.3 and 146.6 nm for a monomer concentration of 2 M, respectively. These heights were less than the thicknesses of PHEMA brushes without lithography patterns, because the height of the PHEMA brushes were dependent upon the grafting site area [36]. Using this strategy, the limit of resolution of the patterned PHEMA brushes approached 350 nm for line patterns.…”

“…The basic strategy for the fabrication of the patterned polymer brushes using the very-large-scale integration (VLSI) process is from the pervious study [27,36]. The fabrication of the patterned HEMA brushes using the very-large-scale integration (VLSI) process is depicted as shown in Fig.…”

“…The chemical compositions of the pristine Si(1 0 0) surface and the Si surfaces at various stages during the surface modification process and the presence of grafted PHEMA brushes were determined using XPS in pervious study [36]. The C 1s core-level spectrum of the PHEMA brushes on the Si surface could be curve-fitted to four peak components having BEs of ca.…”

“…Additionally, patterning on oxidized silicon wafers may be compatible with integrated circuit technology. In pervious study, we focuses on the pattern investigation of PHEMA brushes by using polymerization to chemically amplify surfaces patterned with a VLSI system into patterned PHEMA brushes [36]. This surface-initiated polymerization process provides an avenue toward the rapid fabrication of 750 nm resolution patterns of polymers.…”