An activatable NIR turn-on fluorescent probe for copper (II) ion and live cell imaging

Area of Science:

• Analytical Chemistry
• Chemical Sensing
• Materials Science

Background:

• Accurate detection of copper ions (Cu²⁺) is crucial for environmental and biological monitoring.
• Development of selective and sensitive fluorescent probes is an active area of research.
• Existing methods may lack speed, selectivity, or applicability in real-world samples.

Purpose of the Study:

• To develop a novel fluorescent probe (MB-M) for the selective detection of Cu²⁺ ions.
• To characterize the probe's sensing mechanism and performance.
• To evaluate the probe's utility in biological imaging and environmental sample analysis.

Main Methods:

• Synthesis and characterization of the MB-M fluorescent probe using NMR and HR-MS.
• Spectroscopic analysis (fluorescence and UV-vis) to determine selectivity and sensitivity towards Cu²⁺.
• Computational studies including NCI, QTAIM, NBO, EDD, and FMO analysis to elucidate the interaction mechanism.

Main Results:

• MB-M probe exhibited a distinct color change from colorless to indigo upon binding with Cu²⁺, enabling naked-eye detection.
• The probe demonstrated high selectivity, rapid response (5 minutes), broad pH applicability (2-7), and a low limit of detection (0.33 µM).
• Successful application of MB-M for Cu²⁺ imaging in HepG2 cells and detection in test strips and lake water samples.

Conclusions:

• The MB-M probe is a highly effective tool for sensitive and selective Cu²⁺ detection.
• The probe's performance is supported by detailed computational analysis revealing chemisorption interactions.
• MB-M shows significant potential for real-world applications in biological and environmental monitoring.