Condensation of rhodaminehydrazone with naphthalene-1-carboxaldehyde generates a colourless probe, RDHDNAP that can selectively detect Hg2+ through generation of a pink color along with significant fluorescence enhancement. The binding constant and lowest detection limit for Hg2+ are 2.0 × 105 M−1 and 3 × 10−7 M respectively. Hg2+ imaging in human breast cancer cells (MCF7) under a fluorescence microscope is achieved.
