Controllable construction of ordered three-dimensional microbeads structure and its application in enzyme-linked immunosorbent microarray

In this paper, three-dimensional ordered microbeads structure (3 DOS) was controllably constructed, and was firstly adopted in the enzyme-linked immunosorbent assay (ELISA) for the detection of IgA. The 3 DOS analytical matrix greatly increased the reaction surface and improved the sensitivity of ELISA microassay. Briefly, the 3 DOS dot microarray for bio-analysis was dispensed by the ink-jet micro-device, and assembled in a close box with controlled relative humility (RH). The influence of supporting substrate material, concentration of microbeads suspension, and RH on the conformation of 3 DOS was also discussed in detail. Then the optimum conditions for the uniform and stable 3 DOS for microassay were achieved, and the uniform and stable 3 DOS microarray for the enzyme-linked immunosorbent assay (ELISA) was built up. Finally, the ELISA microassay on the 3 DOS microarray was done to detect IgA and compared with the classic 96-well plate and blank PDMS surface. The results have shown that 15 times reaction time was shortened due to the decreasing of the mass transferring distance; Almost 10 times sensitivity was obtained owing to the increased reaction surface; the large dynamic range was achieved in the 3 DOS ELISA microarray.