Pre-concentration and energy transfer enable the efficient luminescence sensing of transition metal ions by metal-organic frameworks.

The 2,2′-bipyridyl moieties lining the channels of two designer metal–organic frameworks (MOFs), UiO-bpydc and Eu-bpydc (bpydc is 2,2′-bipyridine 5,5′-dicarboxylic acid), recognize and pre-concentrate metal ion analytes and, in the case of Eu-bpydc, transfer energy to the Eu3+ centers, to provide highly sensitive luminescence sensors for transition metal ions.