Chemistry

Materials science

Photochemistry

Fluorescence

Composite material

Bathochromic shift

Physics

Nanotechnology

Organic chemistry

Optics

Catalysis

Rhodamine

Near-infrared spectroscopy

Absorption (acoustics)

Photocatalysis

Rhodamine B

Xanthene

Angewandte Chemie International Edition

Fluorophores and probes are invaluable for the visualization of the location and dynamics of gene expression, protein expression, and molecular interactions in complex living systems. Rhodamine dyes are often used as scaffolds in biological labeling and turn‐on fluorescence imaging. To date, their absorption and emission spectra have been expanded to cover the entire near‐infrared region (650–950 nm), which provides a more suitable optical window for monitoring biomolecular production, trafficking, and localization in real time. This review summarizes the development of rhodamine fluorophores since their discovery and provides strategies for modulating their absorption and emission spectra to generate specific bathochromic‐shifts. We also explain how larger Stokes shifts and dual‐emissions can be obtained from hybrid rhodamine dyes. These hybrid fluorophores can be classified into various categories based on structural features including the alkylation of amidogens, the substitution of the O atom of xanthene, and hybridization with other fluorophores.

Hybrid Rhodamine Fluorophores in the Visible/NIR Region for Biological Imaging