Molecular Quantum Nanosensors Functioning in Living Cells

-terphenyl nanocrystals coated with Pluronic F-127, yielding a coherent spin system with molecular-level uniformity and long spin coherence times under physiological conditions. By chemically suppressing hyperfine interactions, we enhance spectral resolution and demonstrate spatially resolved absolute temperature sensing inside the cytoplasm and nuclei of cancer cells. MoQNs thus offer a chemically tunable, biologically compatible platform for quantum-level detection of thermal and biochemical states of intracellular environments.