Selective and sensitive fluorescent sensor for Pd²⁺ using coumarin 460 for real-time and biological applications

Area of Science:

• Analytical Chemistry
• Materials Science
• Biomedical Engineering

Background:

• Palladium ions (Pd²⁺) are significant environmental pollutants and catalysts.
• Developing selective and sensitive detection methods for Pd²⁺ is crucial for environmental monitoring and industrial processes.
• Existing methods for Pd²⁺ detection can be expensive, complex, or lack sensitivity.

Purpose of the Study:

• To develop a cost-effective and highly sensitive sensor for selective detection of palladium ions (Pd²⁺).
• To utilize the fluorescent properties of coumarin 460 (C460) for Pd²⁺ sensing.
• To validate the sensor's performance in solution, on a strip, and within biological systems.

Main Methods:

• Fabrication of a sensor strip using commercial adhesive tape and coumarin 460 (C460).
• Detection of Pd²⁺ using UV torch, UV chamber, and fluorescence spectrometer.
• Characterization of binding mechanism using ¹H NMR titration and lifetime measurements.
• In-vitro studies using HeLa cell lines for fluorescent imaging.

Main Results:

• Selective and sensitive detection of Pd²⁺ with a low detection limit of 2.5 × 10^-7 M.
• High binding constant values indicating stable complex formation between Pd²⁺ and C460.
• Confirmation of sensing mechanism as Intramolecular Charge Transfer (ICT).
• Successful in-vitro detection of Pd²⁺ in HeLa cells, demonstrating biological compatibility.

Conclusions:

• The developed C460-based sensor offers a cheap, sensitive, and selective method for Pd²⁺ detection.
• The sensor is suitable for both industrial applications and biological environments.
• This approach provides a promising tool for monitoring trace amounts of Pd²⁺ ions.