Radical Shielding Suppresses False Positives in Self-Powered Microfluidic Sensors

Area of Science:

• Electrochemistry
• Environmental Science
• Materials Science

Background:

• Self-powered sensors are crucial for continuous environmental analysis.
• Interfering species often cause false-positive signals, limiting sensor accuracy.
• Existing sensors lack robust anti-interference capabilities.

Purpose of the Study:

• To develop a radical shielding strategy for self-powered sensors.
• To improve the anti-interference performance and selectivity of sensors.
• To enable accurate on-site environmental monitoring in complex matrices.

Main Methods:

• Integration of peroxymonosulfate (PMS) fuel into self-powered sensors.
• Photoactivation of PMS to generate sulfate and hydroxyl radicals (SO4•− and •OH).
• Synergistic coupling of oxidative radicals with molecularly imprinted polymers (MIPs) for enhanced selectivity.

Main Results:

• The radical shield reduced false-positive signal fluctuations from over 600% to below 5%.
• The sensor demonstrated superior resistance to 12 coexisting interferents at 10-fold higher concentrations.
• A microfluidic sensing chip successfully detected levofloxacin (LEV) in river water with high recovery rates (97.68–104.20%).

Conclusions:

• The radical shielding strategy significantly enhances the anti-interference capability and selectivity of self-powered sensors.
• This approach ensures accurate and robust on-site monitoring in complex environmental samples.
• The developed sensor technology holds promise for reliable environmental analysis.