Solvatochromic microcavity ion sensors

A novel copper(II) ion sensor has been developed, achieving both a broad dynamic range and high sensitivity, effectively addressing the limitations of conventional fluorescence-based detection methods. The sensor exploits the hydrolysis reaction between rhodamine B hydrazide (RBH) and copper(II) ions, with optical signal amplification enabled by a whispering-gallery-mode (WGM) microcavity laser. By adjusting the solvent type and utilizing the solvatochromic effect, the detection range of the copper(II) ion and RBH reaction was optimized. The sensor enables rapid, broad dynamic range detection of copper(II) ions, spanning from 5 uM to 3 mM, with a high selectivity, which holds significant potential for future applications in environmental monitoring and biomedical fields.