A "turn-on" fluorescent chemosensor based on peptidase for detecting copper(II)

Area of Science:

• Analytical Chemistry
• Biochemistry

Background:

• Copper(II) ions play crucial roles in biological systems but also contribute to toxicity.
• Developing sensitive and selective detection methods for Cu(II) is vital for environmental monitoring and diagnostics.

Purpose of the Study:

• To design and synthesize a novel fluorescent chemosensor for the detection of copper(II) ions.
• To utilize sequence-specific peptide cleavage for a "turn-on" fluorescence response.

Main Methods:

• A peptide substrate was synthesized, labeled with 6-carboxyfluorescein (FAM) and a Dabcyl quencher.
• The chemosensor's response to Cu(II) was investigated using fluorescence spectroscopy.
• Förster Resonance Energy Transfer (FRET) studies were employed to understand the mechanism.

Main Results:

• The chemosensor exhibited a "turn-on" fluorescence response in the presence of Cu(II) ions in an aqueous medium.
• A linear response range for Cu(II) was observed from 1.0 × 10⁻⁸ to 1.0 × 10⁻⁶ mol dm⁻³.
• A low detection limit of 1.0 × 10⁻⁸ mol dm⁻³ for Cu(II) was achieved.

Conclusions:

• A highly sensitive and selective fluorescent chemosensor for Cu(II) detection was successfully developed.
• The peptidase-mediated cleavage mechanism provides a robust platform for developing metal ion sensors.
• This chemosensor holds promise for real-time monitoring of Cu(II) in various samples.