Study on Enzyme Linked Immunosorbent Assay Using Paper-based Micro-zone Plates

Photolithography was used to pattern hydrophobic design on common quantitative filter paper, and then the paper-based micro-zone plates were successfully fabricated. In order to improve its protein-adsorbing capacity for further signal magnification, modified silicon dioxide (SiO2) micro-beads were deposited onto the surface of paper. Indirect-ELISA for goat anti-rabbit IgG was realized on the 36-zone plates. Taking enzyme-linked goat anti-rabbit IgG as an example, loading SiO2 beads could remarkably increase the quantity of the adsorbed protein by 20%–700%. When this method was used for goat anti-rabbit IgG detection, signals were magnified by 20%–150%, and the linear range of detection was from 3 × 10−12 mmol to 3 × 10−8 mmol per zone. In this manner, bio-reagent consumption was reduced to 3–5 μL per zone, test time dropped to 25 min per plate and the cost of fabrication was reduced to $1.1 per plate. This work suggests a new way for development of new diagnosis devices.

Filter paper was impregnated with SU-8 photoresist, and then was baked in oven after spanning off redundant photoresist. The paper plate was exposed to UV light through a transparent PVC mask and baked another time. After that, it was developed, washed and allowed to dry to form desired pattern.Figure optionsDownload as PowerPoint slide