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Updated: Oct 14, 2025
A11-positive β-amyloid Oligomer Preparation and Assessment Using Dot Blotting Analysis
Published on: May 22, 2018
Ultrasensitive capacitance sensor to detect amyloid-beta 1-40 in human serum using supramolecular recognition of
Hien T Ngoc Le1, Daesoo Kim1, Le Minh Tu Phan2
1Department of Electronic Engineering, Gachon University, Seongnam-si, Gyeonggi-do, 13120, South Korea.
Abstract:
In this paper, we developed a new ultrasensitive capacitance sensor for detection of amyloid beta 1-40 (aβ40) protein (one of Alzheimer's disease core biomarkers) in human serum based on the high supramolecular recognition of the β-cyclodextrin/reduced graphene oxide (β-CD/RGO) nanohybrid toward the anti-aβ40 antibody molecule. The sensor was established by immobilizing specific anti-aβ40 antibody onto the β-CD/RGO nanohybrid functionalized on indium tin oxide micro-disk electrode (anti-aβ40/β-CD/RGO/ITO). Detection of aβ40 in the human serum (HS) using the sensor anti-aβ40/β-CD/RGO/ITO is carried out by capacitance measurement without a redox probe to prevent protein denaturation, serving as a convenient strategy for point-of-care diagnosis. In comparison with other studies, the sensor shows a very low limit of detection of 0.69 fg mL-1 in HS, demonstrating its ability for the ultrasensitive detection of aβ40. Using this sensor, the dissociation constant KD of the binding interaction between anti-aβ40 and aβ40 in HS is found to be 2.9 × 10-7 nM, indicating the high binding affinity of antibody-antigen and the suitability of the anti-aβ40/β-CD/RGO/ITO sensor for aβ40 protein detection. The good selectivity of the anti-aβ40/β-CD/RGO/ITO sensor in the presence of differential analytes was also performed in this paper.
