Directing polyallylamine adsorption on microlens array patterned silicon for microarray fabrication
| Autor: | Steve Blair, Matthew R. Linford, Matthew C. Asplund, Sachin Attavar, Richard J. Gates, Gaurav Saini |
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| Rok vydání: | 2009 |
| Předmět: |
Silicon
Surface Properties Inorganic chemistry Biomedical Engineering chemistry.chemical_element Bioengineering Biochemistry Adsorption X-ray photoelectron spectroscopy Pulmonary surfactant Monolayer Polyamines Reactivity (chemistry) Alkyl chemistry.chemical_classification Chemistry Spectrum Analysis General Chemistry Microarray Analysis Silicon Dioxide Chemical engineering Selective adsorption Microtechnology Hydrophobic and Hydrophilic Interactions |
| Zdroj: | Lab on a chip. 9(12) |
| ISSN: | 1473-0197 |
| Popis: | The selective adsorption of reagents is often essential for bioarray and lab-on-a-chip type devices. As the starting point for a bioarray, alkyl monolayer terminated silicon shards were photopatterned in a few nanoseconds with thousands of wells (spots) using an optical element, a microlens array. Polyallylamine (PAAm), a primary amine containing polymer, adsorbed with little selectivity to the spots, i.e., silicon oxide, over the hydrophobic background. However, at appropriate concentrations, addition of a cationic surfactant to the PAAm deposition solution, cetyltrimethylammonium chloride, prevented the nonspecific adsorption of PAAm onto the hydrophobic monolayer, while directing it effectively to the active spots on the device. A nonionic surfactant was less effective in preventing the nonspecific adsorption of PAAm onto the hydrophobic monolayer. The localized reactions/interactions of adsorbed PAAm with four species that are useful for bioconjugate chemistry: glutaric anhydride, phenylenediisothiocyanate, biotin NHS ester, and an oligonucleotide (DNA) were shown in the spots of an array. The reactivity of PAAm was further demonstrated with an isocyanate. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) played an important role in confirming selective surface reactivity and adsorption. X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry, and wetting confirmed PAAm reactivity on planar substrates. |
| Databáze: | OpenAIRE |
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