Selective and sensitive recognition of Zn²⁺ by a dansyl-derived peptide sensor

Area of Science:

• Chemical Biology
• Analytical Chemistry
• Biochemistry

Background:

• Zinc ions (Zn2+) play critical roles in biological processes.
• Developing selective and sensitive sensors for Zn2+ is crucial for research and diagnostics.
• Existing methods may lack selectivity or require complex procedures.

Purpose of the Study:

• To design and evaluate a dansyl-derived peptide sensor (D1) for selective Zn2+ recognition.
• To assess the sensor's performance, including selectivity, sensitivity, and interference.
• To investigate the sensor's potential for intracellular Zn2+ detection and its cytotoxicity.

Main Methods:

• Fluorescence spectroscopy was used to evaluate the sensor's selectivity and sensitivity towards Zn2+ among various metal ions.
• Binding studies, including Job's plot, were performed to determine stoichiometry and binding affinity.
• pH-dependent fluorescence and interference studies were conducted.
• Cytotoxicity assays and cell imaging were employed to assess biological compatibility and intracellular detection capabilities.

Main Results:

• The sensor D1 exhibited high selectivity for Zn2+ over twelve other metal ions.
• Optimal sensing occurred under basic conditions (pH 8-12).
• A low limit of detection (47.15 nM) and a binding constant of 1.46 × 10^5 M^-1 were determined.
• The sensor demonstrated no significant cytotoxicity and successfully detected intracellular Zn2+.

Conclusions:

• Dansyl-HGHW (D1) is a selective and sensitive peptide-based fluorescent sensor for Zn2+.
• The sensor is non-toxic and effective for intracellular Zn2+ imaging.
• D1 represents a promising tool for biological and chemical sensing applications involving Zn2+.