Recent progress of Si-rhodamine-based probes in intracellular imaging of metal ions and small molecules

Abstract

Si-rhodamines exhibit exceptional photostability and tunable near-infrared emission wavelengths, rendering them highly versatile tools for bioimaging applications—including cellular imaging, super-resolution imaging, in vivo imaging, and the detection of biological small molecules. Driven by the growing interest in Si-rhodamine-based probes and their significant potential for intracellular imaging of metal ions and small molecules, herein we systematically summarize the remarkable advancements in Si-rhodamine-derived fluorescent probes for this purpose. By elaborating on the design principles, reaction mechanisms, and biological applications of probes targeting a broad spectrum of analytes, encompassing metal ions (e.g., Mg²⁺, Ca²⁺, Cu⁺, Cu²⁺, Hg²⁺, Zn²⁺) and small molecules (e.g., HOCl, NO, formaldehyde, H₂S), we delineate how the superior photophysical properties of the Si-rhodamine scaffold underpin their robust performance in intracellular sensing. Furthermore, this review discusses key remaining challenges in the field and highlights promising future opportunities, providing valuable insights to guide subsequent research endeavors in the development of advanced Si-rhodamine-based imaging tools.