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

Abstract

The recognition of the mercury(II) ion (Hg²⁺) 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 Hg²⁺. This switch system exhibited excellent selectivity toward Hg²⁺ by fluorescence (FL), ¹H NMR spectroscopy and the atomic force microscopy (AFM). More importantly, the Hg²⁺-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.