Structure and properties of ICG-Maleimide,ICG-MAL Indocyanine Green ICG-Maleimide CAS2143933-81-5

ICG-MAL is a derivative of ICG (indocyanine green), where MAL represents the maleimide functional group.The structure of ICG-MAL is shown below:

                  H2N-ICG-MAL

ICG-MAL has several important properties:

1. Fluorescent properties: ICG-MAL is a near-infrared fluorescent dye with a strong near-infrared fluorescent signal. It has a high molar absorption coefficient and quantum yield in the near-infrared spectral range, making it an ideal fluorescent probe for near-infrared light imaging and tracking.

2. Reversible binding property: The maleimide functional group of ICG-MAL has a high degree of sulfophilicity, which allows it to undergo a reversible Michael addition reaction with molecules containing sulfhydryl groups (e.g., cysteine residues). This enables ICG-MAL to form covalent binding with molecules containing sulfhydryl groups (e.g., proteins or peptides) under sulfidophilic conditions to achieve labeling or modification of ICG-MAL.

3. Water-soluble: ICG-MAL is a water-soluble compound that can be easily used in biological systems. It can be stabilized under physiological conditions and has good biocompatibility and fluorescence stability in vivo for in vivo near-infrared light imaging and tracking.

4. Biological activity: ICG-MAL has a high light absorption capacity and photothermal conversion efficiency in the near-infrared spectral range, which can be used for optical therapies such as photothermal therapy. In addition, the fluorescence signal of ICG-MAL can be used to monitor drug release and intracellular localization for applications such as drug delivery and cell tracing.

In summary, ICG-MAL is a compound with fluorescent properties, reversible binding properties and water solubility. Its near-infrared (NIR) fluorescence property makes it an ideal fluorescent probe for NIR light imaging and tracking, while its reversible binding property makes it suitable for applications such as protein modification and drug delivery.The properties of ICG-MAL give it a wide range of potential applications in biomedical fields.