A Terbium-Organic Framework Material for Highly Sensitive Sensing of Fe3+in Aqueous and Biological Systems: Experimental Studies and Theoretical Analysis

Abstract

Owing to the paramount importance of iron in biological andenvironmental systems, advanced agents towards the de-tection of iron ions with high sensitivity and selectivity havebeen targeted for decades.Here a new super water-stableagent, namely terbium metal-organic framework (Tb-MOF), [H2N(CH3)2][Tb(cppa)2(H2-O)2],(CTGU-1, CTGU=China Three Gorg-es University, H2cppa= 5-(4-carboxyphenyl)picolinic acid),hasbeen successfully synthesized and demonstrated as a fluo-rescent turn-off sensor for highly sensitive detection of Fe3+with the detection limit of 109M in dimethylformamide (DMF),107M in water and 107M in biological environ-ment,respectively. Such detecting capacity, to our knowledge,is the best compared to those of reported lanthanide-baedMOF fluorescent probes so far. With the combination of firstprinciple calculations, the detecting capacity has been analysedfrom the interaction between metal ions and organic ligands,particularly the effect of metal ions on the frontier molecularorbitals. This work offers a new Ln–MOF probe towards the de-tection of metal irons with high sensitivity and selectivity