Enzymatic DNA Reaction Networks for Orchestrating Stimuli-Dependent Temporal Molecular Pulse.

Area of Science:

• Biotechnology
• Synthetic Biology
• Molecular Diagnostics

Background:

• Cell-free biosensors traditionally use amplitude-based fluorescence, limiting multiplexing due to spectral constraints and cross-talk.
• Existing biosensing methods struggle with complexity and scalability for detecting multiple targets simultaneously.

Purpose of the Study:

• To develop a novel cell-free biosensing platform using temporal dynamics as an orthogonal coding dimension.
• To overcome the multiplexing limitations of current amplitude-based fluorescence biosensors.

Main Methods:

• An enzymatic DNA reaction network (EDRN) was designed, integrating a polymerase-based concentration converter and an exonuclease-driven temporal decoder.
• Input stimuli are translated into standardized universal strands (Us), which are then converted into programmable temporal fluorescence pulses.
• Pulse lifetimes were programmed from minutes to hours by tuning Us production via single- or double-layer converters.

Main Results:

• Demonstrated multiplex bacterial nucleic-acid detection in a single tube using time-color encoding, achieving ten-plex readout with four fluorophores.
• Clinical validation on 32 specimens showed high consistency with sequencing results.
• Achieved programmable pulse lifetimes ranging from approximately 10 minutes to 5 hours.

Conclusions:

• The EDRN establishes a general stimulus-to-time strategy for nucleic-acid circuits.
• This approach significantly expands the multiplexing capacity of fluorescence-based cell-free biosensing.
• The modular design allows orthogonal control over pulse amplitude and lifetime for tunable biosensing.