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Ferritin immobilization on patterned poly(2-hydroxyethyl methacrylate) brushes on silicon surfaces from colloid system.

Chen TY, Chen JK - Colloid Polym Sci (2011)

Bottom Line: The interaction between PHEMA and ferritin protein sheaths in MeOH and n-hexane (good and poor solvent for PHEMA, respectively) was used to capture and release ferritins from fluidic system.The "tentacles" behaver for PHEMA brushes was found through various solvents in fluidic system.Using high-resolution scanning electron microscopy, we observed patterned ferritin Fe cores on the Si surface after pyrolysis of the patterned PHEMA brushes and ferritin protein sheaths, which verify the "tentacles" behaver for PHEMA brushes.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, National Taiwan University of Science and Technology, 43, Sec 4, Keelung Rd, Taipei, 106 Taiwan Republic of China.

ABSTRACT
In this paper, we describe a graft polymerization/solvent immersion method for generating poly(2-hydroxyethyl methacrylate) (PHEMA) brushes in various patterns. We used a novel fabrication process, involving very-large-scale integration and oxygen plasma treatment, to generate well-defined patterns of polymerized PHEMA on patterned Si(100) surfaces. We observed brush- and mushroom-like regions for the PHEMA brushes, with various pattern resolutions, after immersing wafers presenting lines of these polymers in MeOH and n-hexane, respectively. The interaction between PHEMA and ferritin protein sheaths in MeOH and n-hexane (good and poor solvent for PHEMA, respectively) was used to capture and release ferritins from fluidic system. The "tentacles" behaver for PHEMA brushes was found through various solvents in fluidic system. Using high-resolution scanning electron microscopy, we observed patterned ferritin Fe cores on the Si surface after pyrolysis of the patterned PHEMA brushes and ferritin protein sheaths, which verify the "tentacles" behaver for PHEMA brushes.

No MeSH data available.


Related in: MedlinePlus

Side-view SEM images (45° oblique angle) of the Si surface, the PHEMA brushes grafted through 24-h polymerization from 750-nm-wide trenches, and the captured ferritin cores after thermal treatment at 500 °C
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Fig9: Side-view SEM images (45° oblique angle) of the Si surface, the PHEMA brushes grafted through 24-h polymerization from 750-nm-wide trenches, and the captured ferritin cores after thermal treatment at 500 °C

Mentions: To verify this phenomenon, the PHEMA brushes and the ferritin protein sheaths buried within them were then pyrolyzed under O2 in an oven at approximately 500 °C to observe the ferrihydrite cores. The resulting surface displayed the two peak components at BEs of approximately 711.8 and 725.7 eV (Fig. 8d), attributable to Fe–Fe and Fe–O species, respectively, in the Fe 2p core-level spectrum [40]; in addition, the signal in the N 1s core-level spectrum disappeared, confirming that this thermal treatment process decomposed the protein sheaths of the ferritin complexes. Next, we repeated the procedure using a Si wafer presenting the patterned PHEMA brushes. Figure 9 displays the SEM image we obtained from a patterned PHEMA thin film (grafted from 750-nm-wide trenches) after injecting first an aqueous solution of ferritin and then n-hexane through the PHEMA brush surface, cleaning the surface through protein degradation and then subjecting the wafer to pyrolysis at 500 °C to remove all organic compounds. The protein sheaths of the ferritin complexes were removed under these conditions, leaving the Fe core units (average radius of 7 nm) on the trenches grafted from the PHEMA brushes. A few remnant PHEMA brushes are visible in Fig. 9 around the edges of the 750-nm patterned lines. The regions that had not featured PHEMA brushes presented very few ferritin cores, suggesting that only the PHEMA brushes had captured the ferritin complexes, which became buried within the thin film when treated with n-hexane. The absorbed ferritins on the bare silicon region surface were aggregated to macroparticles in n-hexane fluid and removed from the bare silicon region, displaying the distinct regions of bare silicon and dispersed ferritin surface. Our observations reveal that the capture and release of biomacromolecules from aqueous solution onto specific region of Si surfaces are possible when using PHEMA brushes as smart “tentacles” in various solvent fluids.Fig. 9


Ferritin immobilization on patterned poly(2-hydroxyethyl methacrylate) brushes on silicon surfaces from colloid system.

Chen TY, Chen JK - Colloid Polym Sci (2011)

Side-view SEM images (45° oblique angle) of the Si surface, the PHEMA brushes grafted through 24-h polymerization from 750-nm-wide trenches, and the captured ferritin cores after thermal treatment at 500 °C
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3040805&req=5

Fig9: Side-view SEM images (45° oblique angle) of the Si surface, the PHEMA brushes grafted through 24-h polymerization from 750-nm-wide trenches, and the captured ferritin cores after thermal treatment at 500 °C
Mentions: To verify this phenomenon, the PHEMA brushes and the ferritin protein sheaths buried within them were then pyrolyzed under O2 in an oven at approximately 500 °C to observe the ferrihydrite cores. The resulting surface displayed the two peak components at BEs of approximately 711.8 and 725.7 eV (Fig. 8d), attributable to Fe–Fe and Fe–O species, respectively, in the Fe 2p core-level spectrum [40]; in addition, the signal in the N 1s core-level spectrum disappeared, confirming that this thermal treatment process decomposed the protein sheaths of the ferritin complexes. Next, we repeated the procedure using a Si wafer presenting the patterned PHEMA brushes. Figure 9 displays the SEM image we obtained from a patterned PHEMA thin film (grafted from 750-nm-wide trenches) after injecting first an aqueous solution of ferritin and then n-hexane through the PHEMA brush surface, cleaning the surface through protein degradation and then subjecting the wafer to pyrolysis at 500 °C to remove all organic compounds. The protein sheaths of the ferritin complexes were removed under these conditions, leaving the Fe core units (average radius of 7 nm) on the trenches grafted from the PHEMA brushes. A few remnant PHEMA brushes are visible in Fig. 9 around the edges of the 750-nm patterned lines. The regions that had not featured PHEMA brushes presented very few ferritin cores, suggesting that only the PHEMA brushes had captured the ferritin complexes, which became buried within the thin film when treated with n-hexane. The absorbed ferritins on the bare silicon region surface were aggregated to macroparticles in n-hexane fluid and removed from the bare silicon region, displaying the distinct regions of bare silicon and dispersed ferritin surface. Our observations reveal that the capture and release of biomacromolecules from aqueous solution onto specific region of Si surfaces are possible when using PHEMA brushes as smart “tentacles” in various solvent fluids.Fig. 9

Bottom Line: The interaction between PHEMA and ferritin protein sheaths in MeOH and n-hexane (good and poor solvent for PHEMA, respectively) was used to capture and release ferritins from fluidic system.The "tentacles" behaver for PHEMA brushes was found through various solvents in fluidic system.Using high-resolution scanning electron microscopy, we observed patterned ferritin Fe cores on the Si surface after pyrolysis of the patterned PHEMA brushes and ferritin protein sheaths, which verify the "tentacles" behaver for PHEMA brushes.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, National Taiwan University of Science and Technology, 43, Sec 4, Keelung Rd, Taipei, 106 Taiwan Republic of China.

ABSTRACT
In this paper, we describe a graft polymerization/solvent immersion method for generating poly(2-hydroxyethyl methacrylate) (PHEMA) brushes in various patterns. We used a novel fabrication process, involving very-large-scale integration and oxygen plasma treatment, to generate well-defined patterns of polymerized PHEMA on patterned Si(100) surfaces. We observed brush- and mushroom-like regions for the PHEMA brushes, with various pattern resolutions, after immersing wafers presenting lines of these polymers in MeOH and n-hexane, respectively. The interaction between PHEMA and ferritin protein sheaths in MeOH and n-hexane (good and poor solvent for PHEMA, respectively) was used to capture and release ferritins from fluidic system. The "tentacles" behaver for PHEMA brushes was found through various solvents in fluidic system. Using high-resolution scanning electron microscopy, we observed patterned ferritin Fe cores on the Si surface after pyrolysis of the patterned PHEMA brushes and ferritin protein sheaths, which verify the "tentacles" behaver for PHEMA brushes.

No MeSH data available.


Related in: MedlinePlus