With the special nature of confined water pools, reverse micelles (RMs) have shown potential for a wide-range of applications. However, the inherent water insolubility of RMs hinders their further application prospect-especially for applications related to biology. We present herein the first successful transformation,of water-insoluble RMs into water-soluble nanoparticles without changing the confined-aqueous interiors by hydrolysis/aminolysis of arm-cleavable interfacial cross-linked reverse micelles formed from diester surfactant 1. The unique properties exhibited by the aqueous interiors of the resulting pool-buried water-soluble nanoparticles (PWNPs) were demonstrated both by the template synthesis of gold nanoparticles in the absence of external reductants and by the fluorescence enhancement of encapsulated thioflavin T (ThT). Importantly, the unique potential for PWNPs hi biological applications was exemplified by the use of ThT@PWNPS and "cell targeted' ThT@FWNPs as effective,optical imaging agents of living cells. This work conceptually overcomes the application bottleneck of RMs and opens an entry to a new class of functional materials.