Hg2+ wettability and fluorescence dual-signal responsive switch based on a cysteine complex of piperidine-calix[4]arene.

The recognition of the mercury(II) ion (Hg(2+)) is essential because of its extreme toxicity in the environment and food. Hence we reported a novel cysteine (Cys) complex of piperidine-calix[4]arene (L) as a convenient and effective dual-signal responsive switch for Hg(2+). This switch system exhibited excellent selectivity toward Hg(2+) by fluorescence (FL), (1)H NMR spectroscopy and the atomic force microscopy (AFM). More importantly, the Hg(2+)-responsive switch had an important and potential application by water contact angle (CA) on a functional micro-nano silicon surface, including intelligent microfluidic and laboratory-on-chip devices, controllable drug delivery, and self-cleaning surfaces.