Emerging specific selectivity towards mercury(II) cations in water through supramolecular assembly at interfaces

This work deals with the development of ultra-thin film nanosensors for selective and sensitive detection toxic Hg2+ cations in aqueous media. 1,8-Bis[(2-aminoethyl)amino]anthraquinone D0 was functionalized by alkoxy groups different length to prepare ligands D3 D12 linear arrangement two polyamine receptors lipophilic alkyl chains. Chemosensor only binds copper(II) mercury(II) water/methanol (1:1 v/v) solutions no interference other metal cations. The introduction anthraquinone scaffold, which are required form Langmuir monolayers films on solid supports, does not change sensing properties D0. In contrast systems without specific molecular order (i.e. drop-cast films), Langmuir-Blodgett alkoxy-substituted selectively bind cations, even presence ions 10 interfering Selective binding confirmed UV–vis absorption X-ray fluorescence spectroscopies. Thus, films, chemosensor molecules assembled highly ordered supramolecular systems, display a higher selectivity as compared that disordered systems. Ultra-thin sensory allows Hg2+ions water when their concentration is exceeded 0.01 μM, corresponds action level drinking recommended U.S. Environmental Protection Agency. also suitable fabrication electrochemical sensors show similar sensitivity.