Construction of pH-Sensitive “Submarine” Based on Gold Nanoparticles with Double Insurance for Intracellular pH Mapping, Quantifying of Whole Cells and in Vivo Applications

A series of "submarines", which composed of gold nanoparticles and modified with rhodamine and fluorescein derivatives, were presented. With dual sensitive units for both acidic and basic environment, these "gold nano-submarines" not only allow efficient intracellular pH mapping but also provide more accurate quantitative detection of pH alteration under different stimuli with distinct pH quantification range. Moreover, they even have the ability to pass through the blood brain barrier (BBB).