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

Abstract

Abstract The development of a convenient method for the discrimination of typically quenching metal ions such as Cu 2+ , Co 2+ , Ni 2+ , and Fe 3+ is of great interest but still a challenge. By simultaneously incorporating Eu 3+ and organic dye 3,3′‐diethyloxacarbocyanine iodide (DOC) into a metal‐organic framework, MOF‐253, a luminescent sensor array MOF‐253⊃Eu 3+ +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 + , Cu 2+ , Fe 3+ , Co 2+ and Ni 2+ can be well distinguished with a discrimination accuracy of 100% at a concentration as low as 60 µ m . Subsequently, the binary and ternary mixtures of three metal ions (Fe 3+ , Co 2+ , and Ni 2+ ) can also be discriminated successfully. Furthermore, taking Cu 2+ and Ag + as examples, this MOF‐based sensor array can quantify the ion concentration at a low range from 0 to 15 µ m . 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.