Method of making and using hybrid polymeric thin films for bio-microarray applications

Fabrication of DNA Microarrays on Hybrid Polymeric Ultrathin Film Prepared by Self-Assembly of Polyelectrolyte Multilayers

[0054] In this example, we show a novel method for the fabrication of oligonucleotide microarrays with unmodified oligonucleotide probes on hybrid 3-D thin films that are deposited on glass slides by consecutive layer-to-layer adsorption of polyelectrolytes. Unmodified oligonucleotide probes were spotted and immobilized on these multilayered polyelectrolyte thin films (PET) by electrostatic adsorption and entrapment on the porous structure of the PET film. The PET provides higher probe binding capacity, and thus higher hybridization signal than that of the traditional 2-D aminosilane and PLL-coated slides. Immobilized probe densities of 3.4×1012 / cm2 was observed for microarray spots on PET with unmodified 50-mer oligonucleotide probes, which is comparable to the immobilized probe densities of alkyamine-modified 50-mer probes end-tethered on aldehyde functionaliz...

Fabricating Protein Microarrays on Hybrid Film-Coated Glass Slides

[0077] This example describes a method of preparing hybrid 3-D film coated glass slides and the fabrication of protein microarrays. The optical glass slide was cleaned with Piranha solution (30% H2O2:H2SO4 / 1:3), thoroughly rinsed with distilled water and HPLC purified ethanol, and then dried in air or in a dust-free oven at 50° C. The cleaned slide substrate was then immersed in 50 ml of 1.5 mg / mL PSS aqueous solution with a pH value of approximately 2 for 5 minutes, followed by washing with water and exposure to 50 mL of 3 mg / mL PAAH solution (pH 8.0, adjusted by adding NaOH) for 5 minutes. This surface was then washed with pure water and dried with nitrogen or air. The whole procedure was repeated until 12 polyelectrolyte layers (PSS / PEI)6 were deposited on the glass surface. Finally, the glass slide was immersed in 50 ml of 1.5 mg / mL PSS aqueous solution with a pH value of approximately 2 for 5 minutes to form the...

Polyelectrolyte-silica Sol-gel Film Coated Glass Slides For Fabrication of Protein Microarrays

[0082] This example describes a method of preparing 3-D polyelectrolyte-silica sol-gel film coated glass slides and the fabrication of protein microarrays. The optical glass slide was cleaned with 10 N NaOH solution, thoroughly rinsed with distilled water and HPLC purified ethanol, and then dried in air or in a dust-free oven at 50° C. Silica sol-gel stock solution was prepared by mixing 4.0 mL TEOS (tetraethxylorthosilicate), 2.0 mL of deionized water and 100 μL HCl. The sol-gel solution was stirred at room temperature for 3 h. The polyelectrolyte-silica composite cocktail solution was achieved by mechanically blending sol-gel stock solution with polystyrenesulfonate (PSS) aqueous solutions. The volume ratio of the appropriate polyelectrolyte solution to the silica sol-gel stock solution was chosen to control the composition of the composite film. The sol-gel derived films were prepared f...