Fabrication of a hydrophobic/hydrophilic hybrid-patterned microarray chip and its application to a cancer marker immunoassay

Abstract

In this work, we report on a simple process for fabricating a hydrophobic/hydrophilic hybrid-patterned microarray chip for a fast and sensitive immunoassay. Two different types of self-assembled monolayers (SAMs) were used in the fabrication of hydrophilic well patterns and hydrophobic substrates. The hydrophilic/hydrophobic hybrid SAM pattern generates a clear-cut boundary between the sample and the background. A change in the precursor molecules allows for many different types of SAMs to be employed in the fabrication process. Fluorescence image-based detection has previously been used for the quantitative immune-analysis of a specific cancer marker. Here, a titanium-coated glass substrate was utilized to suppress auto-fluorescence signals from substrate backgrounds. Angiogenin (ANG), a small polypeptide implicated in both angiogenesis and tumor growth, was used as a target cancer marker for its validation. Assay results demonstrate that the hybrid-patterned array chip yields a narrower error deviation and a lower coefficient variation than in a conventional 96-well plate ELISA. Furthermore, the sample requirement (1 μL) for the hybridpatterned chip is about 50 times less than that required in an ELISA (at least 50 μL). The proposed hydrophobic/ hydrophilic hybrid-patterned microarray chip is expected to be a highly efficient tool that can be applied to a high throughput immunoassay of a specific cancer marker.

Download PDF = Click Attachment, please.