Bioactive molecules are highly worthwhile to recognize
and explore
the latent pathogenic mechanism. Conventional methods for bioactive
molecule detection, including mass spectrometry and fluorescent probe
imaging, are limited due to the complex processing and signal interference.
Here, we designed enzyme-reaction-assisted programmable transcriptional
switches for the detection of bioactive molecules. The approach is
based on the use of programmable enzyme site-specific cleavage-assisted
DNA triplex-based conformational switches that, upon responding to
bioactive molecules, can trigger the transcription of fluorescent
light-up aptamers. Thanks to the programmable nature of the sensing
platform, the method can be adapted to different bioactive molecules,
and we demonstrated the enzyme-small molecule catalytic reaction combination
of myeloperoxidase (MPO)–hydrogen peroxide (H2O2) as a model that transcriptional switches was capable of
detecting H2O2 and possessed the specificity
and anti-interference ability in vitro. Furthermore,
we successfully applied the switches into cells to observe the detection
feasibility in vivo, and dynamically monitored changes
of H2O2 in cellular oxidative stress levels.
Therefore, we attempt to amalgamate the advantages of enzyme reaction
with the pluripotency of programmable transcriptional switches, which
can take both fields a step further, which may promote the research
of biostimuli and the construction of DNA molecular devices.