A Probeless Capacitive Biosensor for Direct Detection of Amyloid Beta 1-42 in Human Serum Based on an Interdigitated Chain-Shaped Electrode
| Autor: | Hien Thi Ngoc Le, Sungbo Cho, Jinsoo Park |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Amyloid beta
lcsh:Mechanical engineering and machinery capacitive biosensor Peptide 02 engineering and technology Redox Article 03 medical and health sciences 0302 clinical medicine mental disorders lcsh:TJ1-1570 Senile plaques Electrical and Electronic Engineering chemistry.chemical_classification Detection limit amyloid-β 1-42 peptide biology Chemistry Mechanical Engineering interdigitated chain-shaped electrode Self-assembled monolayer anti-aβ antibody 021001 nanoscience & nanotechnology Dissociation constant electrochemical impedance spectroscopy self-assembled monolayer Control and Systems Engineering biology.protein Biophysics 0210 nano-technology Biosensor 030217 neurology & neurosurgery |
| Zdroj: | Micromachines Volume 11 Issue 9 Micromachines, Vol 11, Iss 791, p 791 (2020) |
| ISSN: | 2072-666X |
| DOI: | 10.3390/mi11090791 |
| Popis: | Amyloid beta (a&beta ) 1-42, a peptide that is 1-42 amino acids long, is a major component of senile plaques in the brains of patients with Alzheimer&rsquo s disease. A&beta detection has become an essential antecedence to predict the declining mental abilities of patients. In this paper, a probeless capacitive biosensor for the non-Faradaic detection of a&beta 1-42 peptide was developed by immobilizing a specific anti-a&beta antibody onto a self-assembled monolayer functionalized interdigitated chain-shaped electrode (anti-a&beta /SAM/ICE). The novelty and difference of this article from previous studies is the direct detection of a&beta peptide with no redox probe ((Fe(CN)6)3&minus /4&minus ), which can avoid the denaturation of the protein caused by the metallization (binding of a&beta to metal ion Fe which is presented in the redox couple). The direct detection of a&beta with no redox probe is performed by non-Faradaic capacitive measurement, which is greatly different from the Faradaic measurement of the charge transfer resistance of the redox probe. The detection of various a&beta 1-42 peptide concentrations in human serum (HS) was performed by measuring the relative change in electrode interfacial capacitance due to the specific antibody-a&beta binding. Capacitance change in the anti-a&beta /SAM/ICE biosensor showed a linear detection range between 10 pg mL&minus 1 and 104 pg mL&minus 1, and a detection limit of 7.5 pg mL&minus 1 in HS, which was much lower than the limit of detection for CSF a&beta 1-42 (~500 pg mL&minus 1) and other biosensors. The small dissociation constant Kd of the antibody-antigen interaction was also found to be 0.016 nM in HS, indicating the high binding affinity of the anti-a&beta /SAM/ICE biosensor in the recognizing of a&beta 1-42. Thus, the developed sensor can be used for label-free and direct measurement of a&beta 1-42 peptide and for point-of-care diagnosis of Alzheimer&rsquo s disease without redox probe. |
| Databáze: | OpenAIRE |
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