MnO₂ Nanosheet-based Fluorescence Sensing Platform for Sensitive Detection of Endonuclease

Area of Science:

• Biochemistry
• Nanotechnology
• Analytical Chemistry

Background:

• S1 nuclease is a critical enzyme in DNA metabolism and repair.
• Ultrasensitive detection methods for endonuclease activity are essential for biological research and diagnostics.
• Existing assays for nuclease activity can be time-consuming and complex.

Purpose of the Study:

• To develop a novel, ultrasensitive fluorescence sensing platform for S1 nuclease activity detection.
• To utilize manganese dioxide (MnO2) nanosheets and FAM-labeled single-stranded DNA (FAM-ssDNA) for enhanced sensing.
• To establish a simple and rapid assay for S1 nuclease activity in complex samples.

Main Methods:

• Construction of a fluorescence sensing platform based on MnO2 nanosheets and FAM-ssDNA.
• Exploitation of differential adsorption properties of MnO2 nanosheets towards ssDNA and oligonucleotide fragments.
• Utilizing fluorescence resonance energy transfer (FRET) for signal generation and quenching.
• Monitoring changes in fluorescence intensity upon S1 nuclease-mediated cleavage of FAM-ssDNA.

Main Results:

• The developed platform demonstrated significant fluorescence quenching of FAM-ssDNA adsorbed on MnO2 nanosheets.
• S1 nuclease activity led to the cleavage of FAM-ssDNA, releasing it from MnO2 nanosheets and restoring fluorescence.
• The assay achieved ultrasensitive detection of S1 nuclease activity in the range of 0–20 U mL−1 with a detection limit of 0.05 U mL−1.
• The system showed satisfactory performance in complex biological samples.

Conclusions:

• A novel and ultrasensitive fluorescence sensing platform for S1 nuclease activity has been successfully developed.
• The platform offers advantages of simplicity, speed, and high sensitivity compared to conventional methods.
• This assay holds potential for applications in bioimaging and clinical diagnosis.