Enhancing sensitivity towards electrochemical miRNA detection using an affordable paper-based strategy

Area of Science:

• Analytical Chemistry
• Biotechnology
• Biosensors

Background:

• MicroRNAs (miRNAs) are crucial biomarkers for cancer diagnosis and prognosis.
• Existing miRNA detection methods face limitations in sensitivity, portability, or point-of-care applicability.
• Improving analytical performance of biosensors is essential for early cancer detection.

Purpose of the Study:

• To develop a highly sensitive and portable paper-based electrochemical platform for microRNA detection.
• To enhance the sensitivity of miRNA detection through sample preconcentration.
• To establish a simple and sustainable method for early cancer diagnosis using microRNA biomarkers.

Main Methods:

• A paper-based electrochemical sensor was fabricated by modifying electrodes with a methylene blue (MB)-modified single-stranded DNA (ssDNA) probe complementary to miR-224.
• The sensor was integrated with a wax-patterned chromatographic paper disk for sample preconcentration.
• Electrochemical detection was performed on preconcentrated samples in standard and human serum solutions.

Main Results:

• The developed paper-based sensor achieved a detection limit of approximately 0.6 nM for miR-224 in spiked human serum.
• Employing preconcentration on the chromatographic disk significantly lowered the detection limit to approximately 50 pM.
• The method demonstrated effectiveness in both standard solutions and complex biological matrices like serum.

Conclusions:

• A simple, sustainable, and highly sensitive paper-based electrochemical platform for miRNA detection was successfully developed.
• The integration of chromatographic preconcentration offers a viable strategy to enhance the sensitivity of biosensors for point-of-care applications.
• This approach holds significant potential for advancing analytical and bioanalytical chemistry in early cancer diagnosis and prognosis.