An Electronic Enzyme-linked Immunosorbent Assays Platform for Protein Analysis based on Magnetic beads and AlGaN/GaN high electron mobility transistors

The AlGaN/GaN high electron mobility transistor (HEMT) biosensors have attracted attention due to their high sensitivity, stability, and fast response characteristics. Some related studies have been explored but a problem that the Debye screening exists in the physiological solutions blocks the detection of bio-macromolecules. Herein, a novel fast analytical platform for electronic enzyme-linked immunosorbent assay (e-ELISA) is proposed based on AlGaN/GaN HEMT with Magnetic beads (MBs), MBs-based e-ELISA decouples modified area from sensing surface to simplify the assay. Combining the advantages of e-ELISA and MBs, the resulted analytical platform presents a sensing capability beyond the Debye-screening limit and a novel reusable ability. This scheme offers a fast response toward Prostate specific antigen (PSA) and the lowest concentration of detection is 1 fg mL-1. Compared with conventional AlGaN/GaN HEMT biosensor, it shows higher sensitivity (3.73 μA dec-1) in the linear range (1fg mL-1 to 1pg mL-1), which is within the constraint of the emergency care application. The platform's high sensitivity and fast repeatability show great potential for early rapid diagnosis.