A Chemiluminescent Hydrogen Sulfide Probe with Multimodal Validation for Inflammation Diagnosis in Vivo

Probes capable of simultaneously detecting and differentiating biothiols is crucial yet challenging in optical chemical sensing. In this study, we design a multimodal probe, CL-NBD, through integrating chemiluminescence (high sensitivity and signal-to-noise ratio), absorption (visual discrimination by the naked eye), and fluorescence to distinguish various biothiol species. CL-NBD exhibits distinct signal response modes for hydrogen sulfide (H₂S), cysteine/homocysteine (Cys/Hcy), and glutathione. Upon activation by biothiols, CL-NBD produces chemiluminescence and enhances fluorescence at 515 nm, allowing for selective biothiol detection over other reactive species. Additionally, the probe reveals specific absorbance enhancement at 531 nm for H₂S, facilitating its selective detection. For Cys/Hcy, the probe enhances absorbance at 475 nm and fluorescence at 550 nm, enabling distinctive detection capabilities. Remarkably, CL-NBD was applied to visualize biothiol levels both at the cellular level and in vivo.