A Novel Tetranuclear Copper(I) Iodide Metal–Organic Cluster [Cu₄I₄(Ligand)₅] with Highly Selective Luminescence Detection of Antibiotic

Abstract

Antibiotics in wastewater are very harmful to the environment and human health; their effective detection is important but still challenging. Herein, the first copper­(I) iodine-based antibiotic sensor [Cu4I4­(EBT)5] (denoted as UJN-Cu, EBT = 3-ethyl-1,3-benzothiazole-2-thione) was prepared through a facile solvothermal synthesis method and structurally determined by single crystal X-ray diffraction. The molecular structure of UJN-Cu adopts a chair-like structure of [Cu4I4­(Ligand)5], which is distinctly different from the reported cubane- or chair-like [Cu4I4­(Ligand)4] tetranuclear configurations. Theoretical calculations indicate that the greenish yellow fluorescent emission of UJN-Cu arises from the charge transition between the [Cu4I4] core and EBT ligand. The hydrophobic EBT as a shell of the [Cu4I4] core and the formation of three-dimensional supramolecular structure are responsible for the excellent stability of UJN-Cu in various antibiotic aqueous solutions. UJN-Cu behaves as a sensitive luminescence sensor for detection of tetracycline hydrochloride (TCH) in an aqueous system, and the limit of detection reaches as low as 10 μM. The obvious quenching effect of a tablet of UJN-Cu toward TCH at low concentrations can be obviously detected by the naked eye. Remarkably, the sensor is highly selective for TCH with quenching efficiency 6 times larger than other antibiotics, and can be reused for at least five cycles with the quenching efficiency nearly constant. This study not only represents the first copper­(I) iodine cluster-based sensor for antibiotic detection but also revealed molecular copper­(I) iodine materials are of significance in monitoring water quality.

State of the art methods and challenges of luminescent metal–organic frameworks for antibiotic detection

“…This strong emission is ascribed to the charge transfer triplet excited state between Cu and the ligand, which is consistent with previous relevant mechanism studies of the copper iodine cluster. 84 From the sensing experiments, it was found that the prepared LMOF has the maximum luminescence quenching efficiency toward TCH with a quick response (Fig. 6b).…”

“…83 Recently, two Cu x I y -based LMOFs have been reported as luminescence sensors for monitoring antibiotics. 84,85 In 2018, G. Liu et al synthesized a novel chair-like [Cu 4 I 4 ] cluster-based LMOF, [Cu 4 I 4 (EBT) 5 ] (UJN-Cu, EBT = 3-ethyl-1,3benzothiazole-2-thione) (Fig. 5a).…”

“…5a). 84 Due to the strong coordination bond between Cu(I) in Cu 4 I 4 and the S-donor in the organic ligand, this LMOF has good water stability. In addition, this as-synthesized sample has an obvious luminescence spectrum in the solid state with bright light by naked eyes under UV lamp.…”

Self-assembling of three rare structurally various homomultinuclear CuII complexes derived from a bis(salamo)-based multioxime ligand

“…Coordination chemistry is an important branch of chemistry and is involved many active research fields (Mirza et al, 2018;Liu et al, 2018aLiu et al, , 2019cYamamura et al, 2010;Wang et al, 2012;Duan et al, 2019;Zhang et al, 2020b;Cao et al, 2017). In salen-based ligands [R-CH N-(CH 2 ) n -N CH-R] and their corresponding homometallic and heterometallic complexes, due to their potential application values, intense research in modern coordination chemistry is still ongoing (Bhanja et al, 2020;Maity et al, 2020;Bag et al, 2020;Song et al, 2018;Majumdar et al, 2018;Zhang et al, 2015;Wang et al, 2009;Lo Presti et al, 2010).…”

Hybrid Copper Iodide Cluster-Based Pellet Sensor for Highly Selective Optical Detection of o-Nitrophenol and Tetracycline Hydrochloride in Aqueous Solution

“…To solve these problems, crystalline hybrid copper­(I) iodine clusters formed by copper­(I) iodine cores and coordinated ligands drew intense attention due to their photoactive functions as well as the abundant, nontoxic, and relatively low-cost Cu element. − Also, these clusters show promising applications in the fields of photochemistry and photophysics, for instance, stimuli-responsive luminescence − and solid-state lighting. ,− As a result, they are promising candidates for potential application in environmental contamination optical detection, despite currently remaining less explored . Herein, we report the function synergistic strategy to construct a stable hybrid copper iodine cluster-based optical sensor.…”