Enzyme-instructed self-assembly enabled fluorescence light-up for alkaline phosphatase detection

Area of Science:

• Biochemistry
• Molecular Biology
• Nanotechnology

Background:

• Alkaline phosphatase (ALP) plays roles in normal and pathological tissues.
• Measuring ALP activity with high spatial and temporal resolution using fluorescent probes remains a challenge.

Purpose of the Study:

• To develop a high-performing analytical tool for probing alkaline phosphatase (ALP) activity.
• To utilize enzyme-instructed self-assembly (EISA) for creating a novel fluorescent probe.

Main Methods:

• Enzyme-instructed self-assembly (EISA) was employed to construct the MN-pY probe.
• The fluorescence response of MN-pY to ALP activity was investigated.
• Cellular imaging was performed on HeLa and LO2 cells to assess probe selectivity.

Main Results:

• The MN-pY probe exhibited negligible fluorescence in its free state but showed a ~13-fold increase upon ALP-induced self-assembly.
• Increased fluorescence is attributed to hydrogelation and supramolecular fibril formation of dephosphorylated MN-Y.
• The probe selectively illuminated HeLa cells with high ALP expression over LO2 cells with low ALP levels.

Conclusions:

• MN-pY serves as an effective tool for detecting ALP activity through EISA.
• The probe's mechanism involves dephosphorylation, fibrillation, and hydrophobic pocket formation, enhancing fluorescence.
• MN-pY demonstrates potential for selective cellular imaging and cancer diagnosis based on ALP levels.