Dual-mode fluorescence and UV-vis aptasensor for hepatocellular carcinoma detection using magnetic separation

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Analytical Chemistry

Background:

• HepG2 cells are a common model for hepatocellular carcinoma research.
• Sensitive and specific detection of cancer cells is crucial for early diagnosis and treatment monitoring.
• Existing detection methods may lack sensitivity, specificity, or present challenges in complex biological matrices.

Purpose of the Study:

• To develop a dual-mode aptasensor for sensitive and specific detection of HepG2 cells.
• To utilize magnetic separation and sequential signal conversion for enhanced detection performance.
• To validate the sensor's efficacy in detecting HepG2 cells in human serum.

Main Methods:

• Fabrication of a dual-mode aptasensor using magnetic bead-labeled aptamers (MB-Apt), silver nanoparticles (AgNPs), and CdTe quantum dots (QDs).
• Employing a sequential signal conversion mechanism involving magnetic separation, UV-vis absorption, and fluorescence detection.
• Optimizing reaction conditions and evaluating sensor performance, including linearity, specificity, and accuracy in spiked human serum samples.

Main Results:

• The aptasensor demonstrated sensitive detection with linear ranges for fluorescence (0–2×10⁷ cells/mL, R²=0.985) and UV-vis absorption (R²=0.978).
• The dual-mode system provided self-validation and high anti-interference capabilities.
• Successful detection of HepG2 cells in human serum with high recoveries (96.2–102.5% for fluorescence, 94.8–98.7% for UV/colorimetric) and low RSDs (<5.3%).

Conclusions:

• The developed dual-mode aptasensor offers a sensitive, specific, and reliable method for HepG2 cell detection.
• The sequential signal conversion mechanism and magnetic separation enhance detection performance and reduce interference.
• The sensor's ability to detect HepG2 cells in human serum indicates its potential for practical clinical applications in cancer diagnostics.