An MOF‐Based Luminescent Sensor Array for Pattern Recognition and Quantification of Metal Ions

Abstract

The development of a convenient method for the discrimination of typically quenching metal ions such as Cu2+, Co2+, Ni2+, and Fe3+ is of great interest but still a challenge. By simultaneously incorporating Eu3+ and organic dye 3,3′‐diethyloxacarbocyanine iodide (DOC) into a metal‐organic framework, MOF‐253, a luminescent sensor array MOF‐253⊃Eu3++DOC with three emission centers is generated. Utilizing the diversity of quenching responses of metal ions to the different emission centers, five metal ions including Ag+, Cu2+, Fe3+, Co2+ and Ni2+ can be well distinguished with a discrimination accuracy of 100% at a concentration as low as 60 µm. Subsequently, the binary and ternary mixtures of three metal ions (Fe3+, Co2+, and Ni2+) can also be discriminated successfully. Furthermore, taking Cu2+ and Ag+ as examples, this MOF‐based sensor array can quantify the ion concentration at a low range from 0 to 15 µm. Most probably, this is the first case of simultaneous recognition and quantitation of metal ions in an aqueous solution using an MOF‐based luminescent sensor array. Since a variety of luminescent species including organic dyes and lanthanide ions can be introduced into MOFs to generate multiple‐dimensional luminescence, such strategy will open a new avenue for luminescent sensor assays.

Flexible luminescent non-lanthanide metal–organic frameworks as small molecules sensors

“…This shows extremely strong emission and quantum yields approaching unity. 20,34,36,55,74,75 In ligand-centered (LC) emission, both excitation and emission occur in the same organic linker, while in ligand-to-ligand charge transfer (LLCT), the movement of the electron density happens from a donor ligand to an acceptor ligand upon excitation at a given wavelength (λ ex ). Similar phenomenon occurs in metal-to-ligand charge transfer (MLCT) or ligand-to-metal charge transfer (LMCT).…”

Insights on Luminescent Micro‐ and Nanospheres of Infinite Coordination Polymers

“…While it is hard to design a sensor that can detect a single compound among several others, combining two or more different sensors in arrays can help overcome this limitation. [58,59] As an example, Wang et al synthesized luminescent Zn 2 + and Cd 2 + -based MOFs with 5-((4-carboxyphenyl)formylamino)thiophene-2-carboxylic acid linker. [60] These compounds were also incorporated with red-emitting Eu 3 + ions.…”

Assembly of a Zn(ii) coordination polymer of tetrapyridyl tetraene ligands for selective sensing of CrO42− and Fe3+ in water via luminescence quenching and enhancement

“…In recent decades, great efforts have been made to selectively and sensitively detect metal ions in water. 1,2 Chromium is widely employed in agriculture and industry and is a bioaccumulating and highly poisonous contaminant that cannot be digested. 3 Cr(VI) ions are carcinogenic species that can be harmful to the skin, lung, kidney and liver of humans.…”