Near-infrared (NIR) peptide conjugates are custom peptides covalently linked to fluorescent dyes that absorb and emit light in the near-infrared spectral region, typically around 650-900 nm. These conjugates combine peptide-mediated target recognition with red-shifted fluorescence detection, making them useful for targeted imaging, receptor studies, biodistribution analysis, and fluorescence-guided research.
In contrast to NIR oligonucleotide probes, which are designed for nucleic-acid hybridization, NIR peptide conjugates are usually designed around biological binding. The peptide portion may recognize a receptor, enzyme, transport pathway, tumor-associated marker, cell-penetrating route, or tissue-selective target. The NIR dye provides a detectable optical signal for imaging or analytical readout.
Bio-Synthesis supports custom NIR peptide conjugate builds with flexible dye, linker, labeling-site, purification, and quality-control options. Labeling can often be placed at the N-terminus, C-terminus, or a selected side-chain handle such as lysine, cysteine, or an orthogonal functional group.
Core architecture: NIR Dye — Linker — Peptide. The dye provides fluorescence; the linker manages spacing, solubility, and steric accessibility; the peptide directs the conjugate toward a biological target.