Application of enzyme-responsive fluorescent probes in the precise diagnosis of Hepatocellular Carcinoma

Abstract

Hepatocellular carcinoma (HCC) is a highly lethal malignacy with rising global incidence, where early diagnosis is essential for improving patient outcomes. However, conventional imaging techniques (ultrasound, CT, MRI) and serum biomarkers (e.g., AFP) remain limited in early-stage lesion localization, detection of micro-metastases, and real-time intraoperative navigation. In recent years, enzyme-activatable fluorescent probes, designed around the aberrant expression or activity of tumor-associated enzymes, have shown rapid advances and offer promising strategies for highly sensitive, realtime, and targeted molecular imaging. These probes exploit specific enzymatic activities within the tumor microenvironment, converting non-fluorescent or weakly fluorescent precursors into activated fluorophores or amplifying signals to achieve high-contrast imaging. Their molecular design integrates a recognition unit, fluorophore, and signal-modulation module, enabling switch-on or ratiometric outputs optimized for different enzymatic targets. Compared with traditional molecular imaging, these probes provide faster response, reduced background interference, and enhanced stability in vivo. Emerging developments, including multimodal imaging (e.g., photoacoustic–fluorescence) and dual-enzyme logic-gated systems, further improve diagnostic precision. This review summarizes the design principles, key enzymatic targets, and representative applications of enzyme-activatable fluorescent probes in HCC, and discusses future directions for multimodal integration and clinical translation.