Two-component ratiometric sensor for Cu²⁺ detection on paper-based device.

Area of Science:

• Analytical Chemistry
• Biomedical Engineering
• Environmental Science

Background:

• Copper(II) ions (Cu²⁺) are vital in physiological processes, driving interest in their detection.
• Existing fluorescent probes for Cu²⁺ often suffer from low signal-to-noise ratios and inaccurate responses.
• Ratiometric sensors integrating quenched probes and internal standards for Cu²⁺ detection are rarely reported.

Purpose of the Study:

• To develop a highly selective, paper-based ratiometric sensor for Cu²⁺ detection.
• To overcome the limitations of traditional quenching probes by introducing a novel BODIPY-based probe.
• To establish an accurate, simple, and inexpensive method for Cu²⁺ monitoring.

Main Methods:

• Fabrication of a two-component paper-based device integrating a novel BODIPY-based turn-off probe (P2017) and a reference dye (B001).
• Design of P2017 for enhanced water solubility and selectivity towards Cu²⁺.
• Utilizing B001 as a photostable internal benchmark emitting at 690 nm (excitation 480 nm) unaffected by Cu²⁺.

Main Results:

• The developed sensor demonstrated high selectivity for Cu²⁺ detection.
• The ratiometric approach, combining the quenched P2017 probe and the stable B001 dye, significantly improved signal quality.
• The paper-based device provided accurate and reliable Cu²⁺ measurements.

Conclusions:

• The two-component ratiometric sensor offers a novel strategy for optimizing paper-based devices.
• This method provides an accurate, simple, and cost-effective approach for Cu²⁺ detection.
• Potential applications include human health monitoring and environmental analysis in remote areas.