Light-Triggered\nPlasmonic DNAzyme Walker Enables Precise\nSubcellular Molecular Imaging with Reduced Off-Mitochondria Signal\nLeakage

The\ndevelopment of highly sensitive and precise imaging\ntechniques\ncapable of visualizing crucial molecules at the subcellular level\nis essential for elucidating mitochondrial functions and uncovering\nnovel mechanisms in biological processes. However, traditional molecular\nimaging strategies are still limited by off-mitochondria signal leakage\nbecause of the “always-active” sensing mode. To address\nthis limitation, we have developed a light-triggered activation sequence\nactivated plasmonic DNAzyme walker (PDW) for accurate subcellular\nmolecular imaging by the combination of an organelle localized strategy,\nupconversion nanotechnology, and a plasmon enhanced fluorescence (PEF)\ntechnique. Exploiting the advantage of light activation enables precise\ncontrol over when and where to activate the probe’s sensing\nfunction, effectively reducing off-mitochondria signal leakage as\nvalidated by the dynamic monitoring of changes in off-mitochondria\nsignals during the mitochondrial entry process. Furthermore, by leveraging\nthe PEF capability of triangular gold nanoprisms (Au NPRs), the fluorescence\nintensity can be enhanced by approximately 11.9 times, ensuring highly\nsensitive and accurate subcellular molecular imaging.