On-chip signal amplification of magnetic bead-based immunoassay by aviating magnetic bead chains

In this work, a Lab-on-a-Chip (LOC) platform is used to electromagnetically actuate magnetic bead chains for an enhanced immunoassay. Custom-made electromagnets generate a magnetic field to form, rotate, lift and lower the magnetic bead chains (MBCs). The cost-effective, disposable LOC platform was made with a polymer substrate and an on-chip electrochemical sensor patterned via the screen-printing process. The movement of the MBC5 is controlled to improve the electrochemical signal up to 230% when detecting beta-type human chorionic gonadotropin (beta-hCG). Thus, the proposed on-chip MBC-based immunoassay is applicable for rapid, qualitative electrochemical point-of-care (POC) analysis. (C) 2017 Elsevier B.V. All rights reserved.