Naphthalimide-Based Fluorescent Probe for Portable and Rapid Response to γ-Glutamyl Transpeptidase.

γ-Glutamyl transpeptidase (GGT) is overexpressed in a variety of diseases, making it an important diagnostic criterion for diseases. Herein, a new fluorescence probe based on naphthalimide (Glu-MDA) was developed and employed for the rapid detection of GGT in tumor cells or samples. Alkynylated naphthalimide is the fluorescent core for excellent fluorescence response. The covalent bridging of self-immolative short linkers reduces the steric hindrance between probes and enzyme cleavage sites, which leads to improved enzymatic reaction kinetics. Glu-MDA shows a rapid response and excellent selectivity with a detection limit of 0.044 U/L. This allows the efficient detection of GGT levels in solution and cells. Simultaneously, the construction of Glu-MDA pre-stained test strips provided an innovative strategy for the qualitative detection of GGT activity, helping to detect GGT faster, more portably, and cost-effectively in various scenarios.