A Tetranuclear Copper(II)/Calcium(II) Complex as Dual Chemosensor for Colorimetric and Fluorescent Detection of Non‐Steroidal Anti‐Inflammatory Drugs

Abstract

AbstractThe tetranuclear Cu2+/Ca2+/Ca2+/Cu2+ complex based on Malten ligand has been investigated as a platform for anion binding. Simple organic carboxylates and non‐steroidal anti‐inflammatory drugs (NSAIDs) have been tested, revealing the ability of the platform to bind them. The receiving platform hosts at least two guests in solution although a third anion can be bound, as suggested by X‐ray diffraction analysis. The addition of the anions is accompanied by a color change of the solution, making the system a colorimetric sensor for carboxylates (LOD values comprised between 3.6 and 20.7 ppm). A fluorescent system consisting of the 2‐(3‐oxido‐6‐oxoxanthen‐9‐yl)benzoate (fluorescein anion) linked to the tetranuclear platform has been also prepared and used in a chemosensing ensemble approach to signal the presence of the selected anions (Log K between 2.6 and 5.6 for the addition of two guests). The latter also works in a paper strip test, offering the chemosensor a possible practical application.