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

Photolithography was used to pattern hydrophobic design on common quantitative filter paper, based on which we successfully fabricated the paper-based micro-zone plates. In order to improve its protein-absorbing capability for further signal magnification, modified silicon dioxide (SiO2) micro-beads were deposited onto the surface of paper. Then indirect-ELISA for goat anti-rabbit IgG was applied on the 36-well plates. Taking enzyme linked goat anti-rabbit IgG as an example, loading SiO2 beads could remarkably increase the quantity of the absorbed 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 x 10(-12) mmol/zone to 3 x 10(-8) mmol/zone under given conditions. In this manner, bio-reagent consumption was reduced to 3-5 mu L per zone, test time dropped to 25 min per plate and the cost of fabrication reduced to $1.1 per plate, which indicated a promising application foreground for new disease diagnosis devices.