ICG Hydrazide

ICG Hydrazide is a hydrazide-functionalized derivative of indocyanine green (ICG) designed for covalent attachment to carbonyl-containing biomolecules and materials. In fluorescence imaging workflows, the resulting ICG conjugates provide near-infrared signal readout that is commonly leveraged for optical tracking, labeling, and probe construction. The hydrazide handle enables formation of stable hydrazone linkages under typical conjugation conditions, making it a practical choice for building ICG-labeled reagents from aldehyde/ketone-bearing targets.

1. Fluorescent Bioconjugation

ICG Hydrazide is used by chemical biology and imaging groups to generate ICG-labeled conjugates from aldehyde- or ketone-functional biomolecules, including oxidized proteins, glycoproteins, and carbohydrate-modified constructs. Researchers incorporate the ICG tag to enable near-infrared fluorescence readouts in binding, uptake, and localization studies, where covalent attachment helps maintain signal during washing and multi-step workflows. This reagent is also commonly selected for preparing labeled affinity reagents and tracking probes where the hydrazide provides a straightforward route to stable ICG conjugates.

2. Near-Infrared Imaging Probes

ICG Hydrazide supports the development of near-infrared fluorescence imaging reagents used in microscopy and optical imaging setups that can detect ICG emission. By converting carbonyl-containing scaffolds into ICG conjugates, teams can produce labeled nanoparticles, polymer conjugates, and biomolecule probes for longitudinal optical tracking in research imaging experiments. The hydrazide functionality is particularly valued when the labeling target already contains reactive carbonyl groups, allowing direct preparation of imaging-ready conjugates without requiring pre-installed dye-linker motifs.

3. Biomaterial Surface Labeling

ICG Hydrazide is applied in biomaterials research to introduce ICG fluorescence onto carbonyl-bearing surfaces and coatings, including oxidized polymer films and functionalized hydrogel components. Materials scientists use the resulting fluorescently labeled substrates to visualize distribution, adhesion, and transport phenomena at material interfaces under fluorescence imaging conditions. This approach is also used to create fluorescently traceable material components for assay development, where consistent covalent dye attachment improves reproducibility across fabrication batches and imaging sessions.

4. Oxidized Oligosaccharide Labeling

ICG Hydrazide is frequently used to label oxidized carbohydrates and glycan-containing biomolecules for fluorescence-based studies of glycan presentation and biomolecular interactions. By targeting carbonyl groups introduced during glycan oxidation strategies, researchers can prepare ICG-labeled glycan probes that are then used in binding assays, imaging experiments, and probe libraries for comparative studies. The hydrazide handle helps produce conjugates that retain the near-infrared optical reporter needed for sensitive visual readout in fluorescence imaging instruments.