Polymeric nanosensors for measuring the full dynamic pH range of endosomes and lysosomes in mammalian cells

Honghao Sun, Thomas Lars Andresen, Rikke Vicki Benjaminsen, Kristoffer Almdal

    Research output: Contribution to journalJournal articleResearchpeer-review


    Polymer nanoparticle sensors have been constructed for studying pH in the endocytic pathway in mammalian cells. The pH sensors for fluorescence ratiometric measurements were prepared using inverse microemulsion polymerization with rhodamine as reference fluorophor and fluorescein and oregon green as pH sensitive dyes, which gave a dynamic pH measurement range from 4.1-7.5. Thus, the sensors cover the pH range of almost all intracellular compartments in mammalian cells. Both neutral and cationic polyacrylamide particles were synthesized where (3-acrylamidopropyl) trimethylammonium chloride was used to introduce a net positive charge in the cationic particles. It was found that the positively charged particle sensors were internalized spontaneously by HepG2 cancer cells. These new pH nanosensors are potential tools in time resolved quantification of pH in the endocytic pathway of living cells.
    Original languageEnglish
    JournalJournal of Biomedical Nanotechnology
    Issue number6
    Pages (from-to)676-682
    Publication statusPublished - 2009

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