Ultrasensitive microfluidic paper-based electrochemical/visual biosensor based on spherical-like cerium dioxide...

Area of Science:

• Analytical Chemistry
• Biosensors
• Nanotechnology

Background:

• MicroRNA (miRNA) detection is crucial for disease diagnostics.
• Existing methods often require complex procedures and expensive equipment.
• Development of sensitive and accessible miRNA detection platforms is needed.

Purpose of the Study:

• To develop a sensitive electrochemical biosensor for microRNA detection.
• To utilize microfluidic paper-based analytical devices (μPADs) for enhanced analysis.
• To employ cerium dioxide - gold@glucose oxidase (CeO₂-Au@GOx) as an electrochemical probe for signal amplification.

Main Methods:

• Synthesized gold nanorods (Au NRs) on μPADs for improved conductivity.
• Modified hairpin probes via gold-sulfur bonds.
• Utilized GOx to catalyze glucose, producing H₂O₂, which was electrocatalyzed by CeO₂.
• Performed electrochemical and visual detection methods.

Main Results:

• Achieved a wide linear range (1.0 fM to 1000 fM) with a low detection limit (0.434 fM) via electrochemical measurement.
• Visual detection showed a linear range of 10 fM to 1000 fM with a detection limit of 7.382 fM.
• Demonstrated significant electrochemical signal from H₂O₂ reduction.

Conclusions:

• The developed electrochemical biosensor demonstrates high sensitivity and a low detection limit for miRNA.
• The platform shows potential for practical applications in miRNA detection.
• Integration of Au NRs and CeO₂-Au@GOx probe enhances biosensor performance on μPADs.