Luminescent transition metal–organic frameworks: An emerging sensor for detecting biologically essential metal ions

The vast majority of the reported work on sensing metal ions is primarily based on lanthanide containing luminescent MOFs and relatively few have so far addressed transition metal-based LMOFs. In this review, we particularly focus on the transition-metal based luminescent MOFs (excluding lanthanides and actinides) and their role in sensing trace elements that are biologically essential, through various examples documented thus far. Also included in this article is the brief discussion on the origin of MOFs luminescence which are known to spring from ligands, LMCT, MLCT and guest molecules. This review establishes a refreshed database and will bear some significance to those researchers engaged in creating LMOF sensors for the detection of metal ions.