Cyanine based ratio fluorescent probe and its application in hypochlorite detection.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Fluorescence Spectroscopy

Background:

• Hypochlorite (ClO^-) is vital for immune defense but implicated in diseases like arthritis and neurodegeneration when at elevated levels.
• Accurate detection and imaging of ClO^- are crucial for understanding its role in health and disease.
• Existing detection methods may lack specificity or real-time imaging capabilities.

Purpose of the Study:

• To design and synthesize a novel cyanine-based fluorescent probe (Cy-H) for the ratiometric detection of hypochlorite (ClO^-).
• To investigate the probe's response to ClO^-, including spectral changes and aggregation behavior.
• To evaluate the probe's utility for quantitative analysis and biological imaging of ClO^- in complex systems.

Main Methods:

• Synthesis of a cyanine-based fluorescent probe (Cy-H) with a phenolic hydroxyl group.
• Investigation of the probe's response to hypochlorite, including oxidation and aggregation.
• Spectroscopic analysis to determine emission shifts and establish a linear relationship for quantification.
• Application of the probe for fluorescence imaging in living cells and zebrafish.

Main Results:

• The probe Cy-H exhibited a ratiometric response to hypochlorite, with emission shifting from 700 nm to 485 nm upon oxidation.
• Probe oxidation led to aggregation, facilitating the ratiometric detection mechanism.
• A linear correlation was established between the intensity ratio (I₄₈₅/I₇₀₀) and hypochlorite concentration, with a low limit of detection (0.49 μM).
• Successful imaging of hypochlorite in living cells and zebrafish demonstrated the probe's biological applicability.

Conclusions:

• The developed cyanine-based probe (Cy-H) offers a sensitive and selective method for ratiometric fluorescent detection of hypochlorite.
• The probe's aggregation-based mechanism provides a novel approach for ClO^- sensing.
• Cy-H is a valuable tool for real-time monitoring and imaging of hypochlorite in biological environments, aiding in disease research.