Low-cost goldleaf electrode as a platform for Escherichia coli immunodetection

Area of Science:

• Electrochemistry
• Biosensor technology
• Materials science

Background:

• Gold electrodes are crucial for electrochemical biosensors due to efficient biomolecule functionalization.
• Conventional gold electrode fabrication is expensive, slow, and requires specialized equipment.

Purpose of the Study:

• To present an affordable and rapid method for fabricating electrochemical immunosensors.
• To enable sensitive detection of Escherichia coli (E. coli).

Main Methods:

• Fabrication of gold leaf electrodes (GLEs) using gold leaves, PVC adhesive, and PTFE.
• Patterning of GLEs via laser ablation.
• Characterization using cyclic voltammetry, EIS, SEM, contact angle, and 3D profiling.
• Modification with mercaptopropionic monolayer and anti-E. coli antibodies for E. coli detection.

Main Results:

• Characterization confirmed the functionality of the fabricated gold leaf electrodes.
• The immunosensor demonstrated a low detection limit of 2 CFU/mL for E. coli.
• A linear dynamic range of 10-10^7 CFU/mL was achieved with no false positives from control bacteria.

Conclusions:

• The developed gold leaf electrode is a reliable and reproducible substrate for biosensor applications.
• This method offers a cost-effective alternative for fabricating biosensors.
• The approach is suitable for developing point-of-need biosensors, particularly in resource-limited environments.