With regard to fluorescence quenching commonly observed during metal-ion detection, “turn-on” chemical sensing has been rarely reported, but could be extremely important because it facilitates the selective recognition of target objects of interest against a dark background. A metal–organic framework (MOF) chemosensor has been prepared that serves as an efficient platform for the selective detection of Cu2+ and Cd2+ ions over other metal ions. In particular, this framework shows the highest fluorescence enhancement (≈60-fold relative to Cd-free MOF) for the hazardous metal ion Cd2+ among luminescent MOFs and displays excellent reusability in repeated cycles. The direct diffusion of Cd2+ into the crystal pores has also been visualized for the first time.
Bibliographical noteFunding Information:
This work was supported by a Korea CCS R&D Center (KCRC) grant funded by the Korean government (the Ministry of Science, ICT, & Future Planning (MSIP); NRF-2014M1A8A1049253), by the Basic Science Research Program (NRF-2015R1A2A1A10055658), by the Priority Research Centers Program (NRF2010-0020209), and by PAL. W.R.L. was partly supported by a Korea University Grant. We are grateful to Prof. S. Park at Korea University for helping us measure the fluorescence lifetime.
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- diffusion processes
- metal–organic frameworks
ASJC Scopus subject areas
- Organic Chemistry