Cy7.5 is a near-infrared fluorescent cyanine dye with an emission wavelength greater than 800nm, which falls precisely within the near-infrared window I region of biological tissues. This region is characterized by low background fluorescence from biological tissues and strong penetration of long wavelengths, making Cy7.5-labeled probes commonly used for in vivo imaging in small animals. Cy7.5 exhibits a high extinction coefficient, bright fluorescence, and insensitivity to pH. Cy7.5 derivatives can be covalently linked to biomolecules such as proteins, antibodies, and peptides via reactive functional groups (e.g., NHS esters, maleimides) and are widely applied in fields such as fluorescent immunoblotting, flow cytometry, drug tracking, and deep-tissue imaging[1-4].
References:
[1] Liu Z, Meng X, Zhang Z, et al. Theoretical Study on Spectrum and Luminescence Mechanism of Cy5.5 and Cy7.5 Dye Based on Density Functional Theory (DFT). J Fluoresc. 2025 Jan;35(1):335-342.
[2] Xu S, Zhang P, Heing-Becker I, et al. Dual tumor- and subcellular-targeted photodynamic therapy using glucose-functionalized MoS2 nanoflakes for multidrug-resistant tumor ablation. Biomaterials. 2022 Nov;290:121844.
[3] Li B, Ayala-Orozco C, Si T, et al. Divergent Syntheses of Near-Infrared Light-Activated Molecular Jackhammers for Cancer Cell Eradication. Adv Sci (Weinh). 2024 Dec;11(45):e2405965.
[4] Cilibrizzi A, Wang JT, Memdouh S, et al. PSMA-targeted NIR probes for image-guided detection of prostate cancer. Colloids Surf B Biointerfaces. 2022 Oct;218:112734.
Cy7.5是一种具有近红外荧光的花菁染料，荧光发射波长大于800nm，恰好处于生物组织的近红外窗口I区域，该区域生物组织背景荧光弱且长波长穿透性强，这使得Cy7.5的标记物常应用于小动物活体体内成像中。Cy7.5具有高消光系数、荧光亮度高以及对pH不敏感的特性，Cy7.5衍生物可通过活性基团（如NHS酯、马来酰亚胺等）与蛋白质、抗体、多肽等生物分子共价连接，广泛应用于荧光免疫印迹、流式细胞术、药物追踪及深层组织成像等领域[1-4]。