Paper-Based Fluorogenic Device for Detection of Copper Ions in a Biological System

Area of Science:

• Analytical Chemistry
• Biomedical Engineering
• Materials Science

Background:

• Advanced diagnostics for copper ion detection often require well-equipped labs and trained personnel.
• Resource-limited settings necessitate affordable, user-friendly, and portable diagnostic tools.
• Copper ions (Cu²⁺) play crucial roles in biological systems, making their accurate detection important.

Purpose of the Study:

• To develop an inexpensive, fast, and environmentally friendly paper-based device for detecting copper ions (Cu²⁺) in biological systems.
• To create a novel fluorogenic sensor utilizing fluorescence "turn on" for highly accurate, sensitive, and selective Cu²⁺ detection.
• To demonstrate the device's applicability in resource-limited settings and for point-of-care diagnostics.

Main Methods:

• Fabrication of microfluidic paper-based analytical devices (µPADs) integrated with a novel fluorogenic probe.
• The probe consists of fluorescein moieties and an oxyalkyl chain, designed for fluorescence "turn on" detection of Cu²⁺.
• Characterization of probe's fluorescence emission at 520 nm (excitation 460 nm) and its selective response to Cu²⁺.

Main Results:

• The fluorogenic device achieved a low detection limit of 0.41 pM for Cu²⁺.
• The sensor demonstrated high sensitivity and selectivity, with fluorescence intensity increasing proportionally to Cu²⁺ concentration.
• Effective detection of Cu²⁺ was confirmed in biological samples including urine, serum, and cytochylema.

Conclusions:

• The developed paper-based fluorogenic sensor is cost-effective, user-friendly, and offers high sensitivity and selectivity for Cu²⁺ detection.
• Its portable fabrication and low detection limit surpass existing methods, indicating significant advantages.
• The device shows great application promise for comprehensive sample analysis and point-of-care detection of copper ions in biological systems.