Stabilization of organometallic halide perovskite nanocrystals in aqueous solutions and their applications in copper ion detection.

Stabilization of two-dimensional (2D) PEA2PbI4 (PEA is phenethylammonium) perovskite nanocrystals (PNCs) in water is achieved. By inhibiting the desorption process, the PNCs show exceptional stability for more than 2 months in PEA+ aqueous solutions. Stabilized PNCs are successfully applied for probing Cu2+ in aqueous solution.