Amyloid Beta Detection by Faradaic Electrochemical Impedance Spectroscopy Using Interdigitated Microelectrodes.

Area of Science:

• Biomedical Engineering
• Electrochemistry
• Biosensor Technology

Background:

• Faradaic electrochemical impedance spectroscopy (f-EIS) offers high sensitivity for biosensing.
• Redox reagents used in f-EIS can induce amyloid beta (Aβ) aggregation, compromising detection accuracy.
• Interdigitated microelectrodes (IMEs) are suitable platforms for electrochemical sensing.

Purpose of the Study:

• To develop an f-EIS technique with buffer control to mitigate Aβ aggregation and enhance detection sensitivity.
• To compare the performance of the proposed method against non-faradaic EIS (nf-EIS) and standard f-EIS.
• To analyze the factors influencing sensitivity and impedance changes in Aβ detection.

Main Methods:

• Utilized an interdigitated microelectrode (IME) platform.
• Implemented buffer control within the f-EIS technique.
• Analyzed equivalent circuits for nf-EIS and f-EIS sensors.
• Compared impedance change rates and sensor sensitivities for Aβ detection.

Main Results:

• The proposed buffer-controlled f-EIS method effectively alleviates Aβ aggregation.
• The developed IME sensor demonstrated a 7.40-fold higher sensitivity compared to nf-EIS.
• The proposed sensor achieved a 10.93-fold higher sensitivity than standard f-EIS.

Conclusions:

• Buffer-controlled f-EIS on IME platforms is a promising approach for sensitive and accurate Aβ detection.
• This method overcomes the limitations of traditional f-EIS by preventing reagent-induced aggregation.
• The enhanced sensitivity paves the way for improved diagnostic tools for Aβ-related conditions.