Capacitive Lateral Flow Test for Sub-fM Analysis of Serum HER-2/neu Using a Magnetic Cellulase-Linked Aptamer...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Oncology

Background:

• Lateral flow assays (LFAs) are cost-effective point-of-care (POC) tools for cancer biomarker detection.
• Existing LFAs often lack sensitivity and specificity, and ELISA methods are costly.
• Liquid biopsy analysis of HER-2/neu is crucial for monitoring HER2-positive cancers during targeted therapy.

Purpose of the Study:

• To develop an indicator-free electrochemical lateral flow test (e-LFT) for sensitive and specific detection of serum HER-2/neu.
• To establish e-LFT as a rapid, low-cost POC alternative to traditional methods for liquid biopsy analysis.
• To evaluate the performance of the e-LFT in detecting HER-2/neu in human serum samples.

Main Methods:

• Developed an e-LFT utilizing a cellulase-linked aptamer sandwich strategy.
• Detected HER-2/neu by measuring capacitive changes induced by cellulase digestion of nitrocellulose-coated electrodes.
• Quantified HER-2/neu in human serum with interference mitigation through response correction.

Main Results:

• The e-LFT achieved a detection limit of 0.1 fM HER-2/neu in 10% human serum within 5 minutes.
• Demonstrated high sensitivity (16.13 μC fM⁻¹) and a linear logarithmic concentration range from 0.1 fM to 10 pM.
• Showcased significant advantages over ELISA, being 60x faster and 300x cheaper, with improved accuracy and speed for real-world samples.

Conclusions:

• The developed e-LFT is a highly sensitive, specific, and rapid POC diagnostic tool for HER-2/neu liquid biopsy analysis.
• This technology offers a promising, cost-effective solution for cancer diagnosis and treatment monitoring.
• The e-LFT surpasses existing LFAs, enabling accurate real-time monitoring of HER-2/neu status in HER2-positive cancers.