Chip-based visual detection of microRNA using DNA-functionalized gold nanoparticles

Area of Science:

• Biotechnology
• Nanotechnology
• Molecular Diagnostics

Background:

• MicroRNAs (miRNAs) are crucial biomarkers for various diseases, including cancer.
• Accurate and sensitive detection of miRNAs is essential for early disease diagnosis and monitoring.
• Existing miRNA detection methods can be time-consuming, expensive, or lack sufficient sensitivity.

Purpose of the Study:

• To develop a highly sensitive and convenient biosensor for microRNA detection.
• To utilize gold nanoparticle (AuNP) probes and a gene chip for enhanced miRNA detection.
• To enable rapid, visual, and cost-effective detection of cancer-related miRNAs.

Main Methods:

• Development of a biosensor using gold nanoparticle (AuNP) probes immobilized on a gene chip.
• Hybridization of target miRNAs with capture probes on the chip and subsequent detection via AuNP probes.
• Signal amplification through the reduction of HAuCl4 by H2O2, enabling visual detection.

Main Results:

• A single AuNP probe detected target miRNA at 10 pmol L(-1), with 81.5%-109.1% recovery in fetal bovine serum.
• The biosensor demonstrated consistent results with quantitative PCR (qPCR) for miR-126 in lung cancer tissues.
• Using two AuNP probes improved sensitivity to detect 1 fmol L(-1) of miR-125a-5p.
• Simultaneous detection of lung cancer-related miR-126 and miR-125a-5p was achieved in under 1 hour.

Conclusions:

• The developed biosensor offers a low-cost, rapid, and convenient platform for ultrasensitive and robust visual miRNA detection.
• This technology holds significant potential for early diagnosis and monitoring of diseases, particularly lung cancer.
• The combination of AuNP probes and gene chips provides a powerful tool for advanced molecular diagnostics.