Flexible Hydrophobic Paper-Based Microfluidic Field-Effect Biosensor Amplified by RNA-Cleaving DNAzyme-Based DNA...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Materials Science

Background:

• Magnesium ions (Mg²⁺) are crucial for animal health.
• Blood Mg²⁺ concentration is a key diagnostic indicator for hypomagnesemia.
• Existing diagnostic methods may lack point-of-care accessibility.

Purpose of the Study:

• To develop a flexible, hydrophobic paper-based microfluidic biosensor for point-of-care Mg²⁺ detection.
• To integrate single-walled carbon nanotubes (SWNTs) and a Mg²⁺-specific DNA nanostructure for enhanced sensitivity.
• To create a stable, selective, and anti-interference biosensor for accurate Mg²⁺ monitoring.

Main Methods:

• Synthesized flexible hydrophobic paper using cellulose and octadecyltrichlorosilane for improved mechanical strength and reduced biological interference.
• Functionalized Mg²⁺-specific RNA-cleaving DNAzyme (RCD) with SWNTs for high sensitivity.
• Constructed a DNA nanostructure by self-assembling Y-shaped DNAs onto the SWNT-functionalized RCD, inspired by DNA origami.

Main Results:

• The developed biosensor demonstrated a linear detection range for Mg²⁺ from 1 μM to 1000 μM.
• Achieved a low detection limit of 0.57 μM for Mg²⁺.
• Exhibited excellent stability, selectivity, and anti-interference performance in detection.

Conclusions:

• The flexible hydrophobic paper-based microfluidic biosensor provides a promising platform for point-of-care Mg²⁺ detection.
• The integration of SWNTs and DNA nanostructures enhances biosensor sensitivity and performance.
• This innovative design holds significant potential for real-world Mg²⁺ monitoring applications in animal health.