Ditopic boronic acid and imine-based naphthalimide fluorescence sensor for copper(II)

Area of Science:

• Biochemistry
• Cell Biology
• Chemical Biology

Background:

• Copper ions are vital for biological functions but toxic at high concentrations.
• Developing selective and sensitive copper sensors is crucial for cellular research.
• Reversible fluorescent chemosensors are rare, especially those utilizing boronic acid moieties.

Purpose of the Study:

• To investigate a novel naphthalimide derivative (BNP) as a selective fluorescent sensor for Cu(2+) in living cells.
• To explore the unique properties of BNP, including its reversible detection mechanism and interaction with fructose.
• To visualize the cellular uptake and distribution of BNP in HeLa cancer cells.

Main Methods:

• Synthesis and characterization of the naphthalimide derivative BNP.
• Confocal fluorescence microscopy for cellular imaging.
• Two-photon fluorescence lifetime imaging microscopy (2pFLIM) for detailed analysis.

Main Results:

• BNP selectively detected Cu(2+) ions in living cells with enhanced fluorescence.
• The BNP-Cu(2+) adduct exhibited fluorescence enhancement in the presence of fructose.
• Cellular uptake and distribution of BNP in HeLa cancer cells were successfully imaged.

Conclusions:

• BNP is a novel, reversible fluorescent chemosensor for Cu(2+) with potential applications in biological studies.
• The fructose-induced fluorescence enhancement offers additional sensing capabilities.
• Advanced microscopy techniques confirmed the cellular applicability of BNP for copper ion imaging.