Micropatterned avidin arrays on silicon substrates via photolithography, self‐assembly and bioconjugation

Processes for micropatterning protein arrays on inorganic substrates have gained attention in the development of biosensors and clinical diagnostics. This study demonstrates a chemically selective method based on photolithographic deposition of gold patterns with the subsequent attachment of functionalized alkanethiols via molecular self-assembly. Selective capping of carboxy groups on alkanethiols by N-hydroxysuccinimide esters allowed the deposition of methoxypoly(ethylene glycol) silane as a blocking agent on unpatterned regions. Carboxylates were used to couple a form of avidin to create a microarray of protein. This microarray was successfully probed with biotinylated quantum dots. In-process characterization methods included grazing-angle Fourier-transform IR spectroscopy, ellipsometry, contact-angle goniometry, atomic-force microscopy and fluorescence microscopy.