Correlating Molecule Counts with Stress Granule Size Using Novel Platinized Carbon Nanopore Electrodes

Stress granules (SGs) are membraneless dynamic structures formed through liquid-liquid phase separation (LLPS) under stress conditions; they can pause nonessential translation and reprogram gene expression to cope with stress, thus being crucial for cell survival. This study pioneers an oxidative stress model that links SG size to redox regulation. Novel platinized carbon nanotube nanopipettes (Pt-CNTNPs) were employed for SG impact electrochemical cytometry (SGIEC) and intracellular SGIEC (ISGIEC) measurements, correlating H₂O₂ content with SG dimensions through a size-exclusion mechanism. Gaussian fitting quantified the distribution of H₂O₂ molecule number, and data from PEG8000 solutions demonstrated that intracellular-extracellular content number disparities are likely attributable to macromolecular crowding. All of the results confirm that H₂O₂ generation in SGs is governed by an interfacial electric field. By establishing a quantitative SG-mediated redox framework, this study provides novel insights into LLPS and opens avenues for targeted therapies and biomimetic materials.