Development of Polymeric Nanoprobes with Improved Lifetime Dynamic Range and Stability for Intracellular Oxygen Sensing

A class of core‐shell nanoparticles possessing a layer of biocompatible shell and hydrophobic core with embedded oxygen‐sensitive platinum‐porphyrin (PtTFPP) dyes is developed via a radical‐initiated microemulsion co‐polymerization strategy. The influences of host matrices and the PtTFPP incorporation manner on the photophysical properties and the oxygen‐sensing performance of the nanoparticles are investigated. Self‐loading capability with cells and intracellular‐oxygen‐sensing ability of the as‐prepared nanoparticle probes in the range 0%–20% oxygen concentration are confirmed. Polymeric nanoparticles with optimized formats are characterized by their relatively small diameter (<50 nm), core‐shell structures with biocompatible shells, covalent‐attachment‐imparted leak‐free construction, improved lifetime dynamic range (up to 44 μs), excellent storage stability and photostability, and facile cell uptake. The nanoparticles’ small sensor diameter and core‐shell structure with biocompatible shell make them suitable for intracellular detection applications. For intracellular detection applications, the leak‐free feature of the as‐prepared nanoparticle sensor effectively minimizes potential chemical interferences and cytotoxicity. As a salient feature, improved lifetime dynamic range of the sensor is expected to enable precise oxygen detection and control in specific practical applications in stem‐cell biology and medical research. Such a feature‐packed nanoparticle oxygen sensor may find applications in precise oxygen‐level mapping of living cells and tissue.