Highly Sensitive Micropatterned Interdigitated Electrodes for Enhancing the Concentration Effect Based on...

Area of Science:

• Biomolecular detection
• Microfluidics
• Dielectrophoresis

Background:

• Dielectrophoresis (DEP) concentration effect is crucial for sensitive biomolecule detection.
• Interdigitated microelectrodes (IMEs) are commonly used for DEP-based sensing.
• Enhancing the electric field gradient in IMEs can improve DEP performance.

Purpose of the Study:

• To investigate the use of microstructures to enhance the DEP concentration effect.
• To improve the sensitivity of amyloid beta 42 (Aβ42) and tau-441 detection using patterned IMEs.
• To reduce the optimal voltage required for concentrating Aβ42 and tau-441.

Main Methods:

• Patterning microstructures between IMEs to increase electric field gradients.
• Measuring impedance changes for Aβ42 and tau-441 detection under varying conditions.
• Quantifying DEP concentration effect by counting gold-conjugated secondary antibody particles.
• Evaluating impedance changes with varying concentrations of Aβ42 and tau-441.

Main Results:

• Microstructures increased the electric field gradient by approximately 6.61-fold compared to bare IMEs.
• Optimal voltage for concentrating Aβ42 decreased from 0.8 Vpp to 0.5 Vpp; for tau-441, from 0.9 Vpp to 0.6 Vpp.
• Impedance change was 2.64-fold higher for Aβ42 and 1.59-fold higher for tau-441 detection due to enhanced DEP concentration.
• Verified enhanced DEP concentration effect through gold particle counting and impedance measurements.

Conclusions:

• Microstructures significantly enhance the DEP concentration effect in IMEs.
• The enhanced DEP effect leads to improved sensitivity for detecting Aβ42 and tau-441.
• Patterned IMEs offer a promising approach for highly sensitive biomarker detection.