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 SiO2 nanoislands (on Si).

Creating highly dense and uniform protein and DNA microarrays through photolithography and plasma modification of glass substrates.

We demonstrate a method to create high density protein microarrays with excellent spot uniformity using photolithography and plasma processing on low cost commercially available microscope glass slides. Protein deposition and fluorescence signal evaluation on these substrates are performed by standard arrayers and scanners. To this end, spots of commercial photoresists (AZ5214, SU8 and Ormocomp(®)) were defined through lithography on glass substrates followed by short SF(6) plasma treatment and selective protein adsorption on these spots with respect to glass (spot to background fluorescence signal ratios 30:1 to 40:1) was demonstrated using model protein binding assays.

High-density protein patterning through selective plasma-induced fluorocarbon deposition on Si substrates.

A novel method for fabrication of protein microarrays through selective plasma-induced modification of patterned substrates is presented. Exposing Si substrates bearing SiO(2) or Si(3)N(4) patterns to a c-C(4)F(8) plasma in a high-density plasma reactor, a fluorocarbon (FC) film was selectively deposited on Si areas, whereas the SiO(2) or Si(3)N(4) patterns were simultaneously etched. Optimizing the plasma parameters such as power, bias voltage and gas pressure, patterned substrates with highly selective protein adsorption capacities were obtained.