Ratiometric core/shell Nanosensors for Simultaneously Measuring Mitochondrial ATP Production and Oxygen Consumption in Living Cells.

A ratiometric dual nanosensor for simultaneously measuring intracellular ATP and oxygen concentration was developed. The nanosensor had a unique core/shell nanostructure, and the hydrophobic oxygen sensitive probe and reference dye are physically encapsulated inside polystyrene nanoparticles. The outer surface of polystyrene nanoparticles was coated with a thin layer of hydrophilic silica oxide, then the ATP-sensitive probe was covalently labelled on the silica surface. The synthesized nanoparticles have uniform size, excellent control in both size and morphology. They are monodispersed and had good stability in aqueous solution. Their net positive surface charge fascinates their uptake by living cells, and the nanosensor showed good biocompatibility with rather low cytotoxicity. The high photostability and fully reversible response of the dual nanosensors made them suitable to measure the oxygen consumption and ATP production in real time. Therefore, we can directly measure the oxygen consumption rate and ATP production, and calculate the P/O ratio in real-time and directly in living cells. Supplementary Information: The online version contains supplementary material available at 10.1007/s43657-025-00234-9.