Ferritin-Enhanced Direct MicroRNA Detection via Controlled Radical Polymerization

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Molecular Diagnostics

Background:

• Accurate quantitative detection of nucleic acids is critical for cancer genetic testing.
• Developing low-cost, highly sensitive direct gene detection methods is essential for cancer prevention and treatment.
• microRNA-21 is a known early biomarker for lung cancer.

Purpose of the Study:

• To develop an ultrasensitive electrochemical biosensor for the direct detection of microRNA-21.
• To utilize a ferritin-enhanced atom-transfer radical polymerization (Ft-ATRP) process for signal amplification.
• To establish a cost-effective and highly sensitive method for early lung cancer detection.

Main Methods:

• Fabrication of an electrochemical biosensor using peptide nucleic acid probes on a gold electrode.
• Employing ferritin to mediate the aggregation of hydrophilic nitroxide radical monomers (MATMP).
• Utilizing Ft-ATRP to form polymer chains with electrochemical signals on the target microRNA-21 for signal amplification.

Main Results:

• The biosensor achieved an ultrasensitive limit of detection (LOD) for microRNA-21 as low as 6.03 fM.
• The detection concentration range was established from 0.01 to 100 pM with high linearity (R² = 0.994).
• The developed RNA biosensor demonstrated robust performance in analyzing complex samples with simple operation.

Conclusions:

• The ferritin-enhanced biosensor provides a highly sensitive and direct method for microRNA-21 detection.
• This innovative approach shows significant potential for early lung cancer screening and identification.
• The biosensor's components and detection process exhibit good water solubility, facilitating practical application.