1 research outputs found
Plasma-Assisted Nanoscale Protein Patterning on Si Substrates via Colloidal Lithography
Selective immobilization of proteins
in well-defined patterns on
substrates has recently attracted considerable attention as an enabling
technology for applications ranging from biosensors and BioMEMS to
tissue engineering. In this work, a method is reported for low-cost,
large scale and high throughput, selective immobilization of proteins
on nanopatterned Si, based on colloidal lithography and plasma processing
to define the areas (<300 nm) where proteins are selectively immobilized.
A close-packed monolayer of PS microparticles is deposited on oxidized
Si and, either after microparticle size reduction or alternatively
after metal deposition through the PS close-packed monolayer, is used
as etching mask to define SiO<sub>2</sub> nanoislands (on Si). C<sub>4</sub>F<sub>8</sub> plasma was used to selectively etch and modify
the SiO<sub>2</sub> nanoislands while depositing a fluorocarbon layer
on the Si surface. The plasma-treated surfaces were chemically characterized
in terms of functional group identification through XPS analysis and
reaction with specific molecules. Highly selective protein immobilization
mainly through physical adsorption on SiO<sub>2</sub> nanoislands
and not on surrounding Si was observed after C<sub>4</sub>F<sub>8</sub> plasma-induced chemical modification of the substrate. The thickness
of the immobilized protein monolayer was estimated by means of AFM
image analysis. The method reported herein constitutes a cost-efficient
route toward rapid, large surface, and high-density patterning of
biomolecules on solid supports that can be easily applied in BioMEMS
or microanalytical systems