Fluorescence Method-Based Nonlinear Hybridization Chain Reaction for Highly Sensitive and Specific Detection of HER2

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Molecular Diagnostics

Background:

• Human epidermal growth factor receptor 2 (HER2) is a key biomarker for gastric cancer targeted therapy.
• Current tissue-based tests (IHC, FISH) are gold standards, but serum HER2 offers a less invasive monitoring option.
• Existing serum HER2 assays lack the sensitivity required for effective disease monitoring.

Purpose of the Study:

• To develop a highly sensitive fluorescence assay for detecting serum HER2.
• To utilize nonlinear hybridization chain reaction (NHCR) coupled with a HER2-specific aptamer for enhanced signal amplification.
• To provide a novel tool for accurate and noninvasive serum HER2 detection.

Main Methods:

• Development of a fluorescence assay employing nonlinear hybridization chain reaction (NHCR) and a HER2-specific aptamer (HB5).
• NHCR facilitates branching-mediated exponential amplification for nonlinear signal growth, surpassing linear HCR.
• Validation of the assay's performance using standard solutions and clinical serum samples.

Main Results:

• The assay demonstrated a wide linear range (0.5-90 ng·mL⁻¹) with a low detection limit of 38 pg·mL⁻¹.
• High specificity, reproducibility, and stability were observed for HER2 detection.
• Results from clinical samples showed strong correlation with the chemiluminescence immunoassay (CLIA), with recoveries from 95.4% to 109.6%.

Conclusions:

• The NHCR-based fluorescent assay provides a sensitive and accurate method for serum HER2 detection.
• This approach offers a valuable, noninvasive tool for monitoring gastric cancer patients.
• The assay is characterized by simple operation and cost-effectiveness.