Abstract
The 1,3-dipolar cycloaddition reaction (click chemistry approach) was employed to create a hexa-ferrocenylated 1,3,5-triphenylbenzene derivative. Leveraging the presence of metal-chelating sites associated with 1,2,3-triazole moieties and 1,4-dinitrogen systems (ethylenediamine-like), as well as tridentate chelating sites (1,4,7-trinitrogen, diethylene triamine-like) systems, the application of this molecule as a chemosensor for divalent transition metal cations was investigated. The interactions were probed voltammetrically and spectrofluorimetrically against seven selected cations: iron(II) (Fe(2+)), cobalt(II) (Co(2+)), nickel(II) (Ni(2+)), copper(II) (Cu(2+)), zinc(II) (Zn(2+)), cadmium(II) (Cd(2+)), and manganese(II) (Mn(2+)). Electrochemical assays revealed good detection properties, with very low limits of detection (LOD), for Co(2+), Cu(2+), and Cd(2+) in aqueous solution (0.03-0.09 μM). Emission spectroscopy experiments demonstrated that the title compound exhibited versatile detection properties in solution, specifically turn-off fluorescence behavior upon the addition of each tested transition metal cation. The systems were characterized by satisfactory Stern-Volmer constant values (10(5)-10(6) M(-1)) and low LOD, especially for Zn(2+) and Co(2+) (at the nanomolar concentration level).