A novel highly luminescent LnMOF film: a convenient sensor for Hg2+ detecting

A highly luminescent LnMOF {[Eu-2(bqdc)(3)(H2O)(DMF)(3)]center dot 0.5DMF center dot H2O}(n) (1, bqdc = 2,2'-biquinoline-4,4'-dicarboxylate) was designed and synthesized. It was characterized by single crystal X-ray diffraction, PXRD, TGA, EA and FT-IR. A new strategy for preparing mechanically robust MOF thin films was developed by electrodeposition in combination with subsequent solvothermal synthesis. A portable sensor device prototype consisting of a film of 1 was conveniently fabricated by using this new strategy and this sensor device exhibits a highly selective response to Hg2+. Its luminescence quenching can be distinguished clearly with the naked eye when illuminated by a handy UV banknote detector. The diffusion kinetics of Hg2+ into the LnMOF film is first proposed.