This study focused on fabricating a target-specific electrical biosensor with high sensitivity and dynamic range by embedding a hydrogel, that incorporated a much larger number of antibodies in the reaction region of the sensor, allowing all biomolecules except the target molecules to be filtered off. The biosensor is comprised of a three-dimensional interdigitated microelectrode (3D IMEs) with much higher aspect ratios than conventional IMEs and a hydrogel with a 3D mesh structure. The hydrogel increases the number of antibodies in the reaction region of the 3D IMEs by approximately 1,000-fold and enhances the impedance change induced by the specific binding of biomolecules. The hydrogel density is altered according to the target biomolecules. The impedance change by Aβ42 binding was maximized to approximately 12.135 ± 0.903% in the 3D IMEs with a ‘dense’ hydrogel. The change by prostate-specific antigen (PSA) binding was maximized in the 3D IMEs with a ‘loose’ hydrogel. Thus, the dynamic range and sensitivity for detecting Aβ42 were enhanced by a maximum of two orders and by approximately 2.58-fold compared to planar IMEs. These results demonstrate the high performance of the hydrogel-embedded 3D IMEs and its applicability for biological fluid-based diagnosis.
Bibliographical notePublisher Copyright:
© 2019 Elsevier B.V.
- Amyloid beta
- High sensitivity and selectivity
- Porosity tunable hydrogel
- Three-dimensional interdigitated microelectrodes
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry