Paper-Based DNA Biosensor for Rapid and Selective Detection of miR-21

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Cancer Diagnostics

Background:

• Cancer is a leading global cause of death, emphasizing the need for accessible early detection methods.
• Healthcare disparities limit access to advanced cancer diagnostics, particularly in resource-limited settings.
• MicroRNAs (miRs), such as miR-21, are promising biomarkers for early cancer detection due to their differential expression.

Purpose of the Study:

• To develop a cost-effective, sensitive, and rapid electrochemical paper-based biosensor for the quantitative detection of miR-21.
• To enable point-of-care cancer diagnostics suitable for low-resource environments.
• To address healthcare disparities in cancer screening and diagnosis.

Main Methods:

• Fabrication of an electrochemical paper-based biosensor using gold inkjet printing.
• Immobilization of single-stranded DNA-21 (ssDNA-21) on gold nanoparticles (AuNPs) via thiolated self-assembled monolayers.
• Detection of miR-21 through hybridization, leading to changes in electron transfer and current suppression.

Main Results:

• The biosensor achieved a linear detection range of 1 fM to 1 nM for miR-21.
• Demonstrated high sensitivity with a detection limit of 0.35 fM in serum.
• Exhibited a rapid response time of 15 minutes and excellent selectivity against interferents.

Conclusions:

• The developed gold inkjet-printed electrochemical paper-based biosensor provides a viable tool for sensitive and specific miR-21 detection.
• This technology holds significant potential for advancing cost-effective, point-of-care cancer diagnostics in underserved regions.
• The study highlights a promising approach to mitigate healthcare disparities in cancer diagnostics.