Near-Infrared Light Activated Nucleic Acid Cascade Recycling Amplification for Spatiotemporally Controllable Signal Amplified mRNA Imaging

The expression level and subcellular distribution of mRNA dynamically changed during the different cell circles. Spatiotemporally controllable signal amplification methods capable of controlling the when and where of the amplification process could allow the sensitive mRNA imaging of selected living cells at dictated time-intervals of the cell life-cycle. However, the present methods for amplified mRNA imaging are hard to control the where and when of the signal amplification due to the lack of an effective strategy to precisely trigger and control the signal amplification process. Herein, we present a conceptual study termed as photocontrollable nucleic acid cascade recycling amplification which uses near-infrared (NIR) light to precisely control and trigger the whole process. This strategy is achieved by integrating photocontrollable nucleic acid displacement reaction with exonuclease III (EXO III) assisted nucleic acid cascade recycling amplification and combination with upconversion nanoparticles (UCNPs), thus resulting in a NIR light activatable signal amplification. As a proof of concept, we demonstrate this developed NIR light triggered signal amplification process in selected living cancer cells for spatiotemporally controllable signal amplified mRNA imaging.