Assembly fluorescent probe-based detection of gamma-glutamyl transferase activity in tumor

Detection of γ-glutamyltransferase (GGT) activity in cancer cells is crucial for understanding tumor progression and metabolic dysregulation. However, the accurate detection of GGT remains challenging due to its complex intracellular distribution and interactions with other enzymes. This study introduces a novel hemicyanine-based sensor, named GP, designed for the sensitive and real-time detection of GGT in tumor cells. By leveraging the unique optical properties of hemicyanines in the near-infrared spectrum, the GP sensor enables deeper tissue penetration and minimizes background interference, which is essential for tumor imaging. The sensor incorporates a GGT-specific recognition sequence that selectively binds to GGT, facilitating precise monitoring of its enzymatic activity through fluorescence signals generated by intramolecular charge transfer (ICT). Our results show that the GP probe exhibits high selectivity for GGT, distinguishing it from other biological molecules. Evaluation under tumor-relevant conditions confirms the probe's robustness for both research and clinical applications. In cancer cell models, GP successfully detects increased GGT activity, suggesting its potential for non-invasive monitoring of tumor dynamics. Overall, this study demonstrates GP as a promising tool for the accurate detection of GGT activity, with significant implications for understanding cancer-related metabolic changes and tumor biology.