Design and Synthesis of Heterobimetallic Ru(II)–Ln(III) Complexes as Chemodosimetric Ensembles for the Detection of Biogenic Amine Odorants

Abstract

The detection of neutral biogenic amines plays a crucial role in food safety. Three new heterobimetallic Ru(II)-Ln(III) donor-acceptor complexes, KPrRu, KNdRu, and KSmRu, K{[Ru((II))((t)Bubpy)(CN)4]2-Ln((III))(H2O)4} (where (t)Bubpy = 4,4'-di-tert-butyl-2,2'-bipyridine), have been synthesized and characterized. Their photophysical and X-ray crystallographic data were reported in this study. These complexes were found to be selective for biogenic amine vapors, such as histamine, putrescine, and spermidine, with a detection limit down to the ppb level. The sensitivities of these complexes to the amines were recorded as ~log K = 3.6-5.0. Submicron rods of the complexes, with a nanoscale diameter and microscale length, were obtained through a simple precipitation process. Free-standing polymeric films with different degrees of porosity were fabricated by blending the submicron rods with polystyrene polymer. The polymer with the highest level of porosity exhibited the strongest luminescence enhancement after amine exposure. Real time monitoring of gaseous biogenic amines was applied to real fish samples (Atlantic mackerel) by studying the spectrofluorimetric responses of the Ru(II)-Ln(III) blended polymer film.

A polymorphic lanthanide complex as selective Co2+ sensor and luminescent timer

“…Some organic molecules, silver and gold oxide nanoparticles were applied to detect Co 2+ [26][27][28][29][30], and a lanthanide show sensing effect to Zn 2+ , Cd 2+ and Co 2+ at the same time, but it is not a selective Co 2+ sensor [27]. That is, though lanthanide complex had been reported to detect many kinds of ions and molecules [1,3,[31][32][33][34][35][36][37][38][39][40], due to its unique photophysical properties (such as microsecond to millisecond lifetimes, characteristic and narrow emission bands, as well as large Stokes shifts), the selective sensing to Co 2+ is not reported. Therefore, selective and sensitive sensing Co 2+ by luminescent lanthanide complex is urgent and interesting.…”

Lanthanide Photoluminescence in Heterometallic Polycyanidometallate-Based Coordination Networks

“…Beside the homoligand polycyanidometallates, [M(CN) x ] n− (x = 2, 4, 6, and 8), the photo-luminescent d–f coordination networks were prepared using the heteroligand tetracyanidometallate complexes, [M II (L)(CN) 4 ] 2− (M = Ru, Os), where two positions of the octahedron are blocked by the aromatic N,N-bidentate organic ligands, L [111,112,113,114,115,116,117,118,119]. Depending on the selected L ligand, exemplified by 2,2’-bipyridine (2,2’-bpy), 1,10-phenanthroline (phen), or 2,2’-bipyrimidine (bpym), these heteroligand cyanide complexes of Ru II and Os II reveal the intrinsic green to red emission of the metal-to-ligand charge transfer (MLCT) origin [33].…”

“…The innovative luminescent functionality of heteroligand tetracyanidometallates was shown for the [Ru II ( t Bubpy)(CN) 4 ] 2− ion bearing the tert -butyl derivative of 2,2’-bipyridine [118,119]. This anion embedded in the bimetallic K[Ln III (H 2 O) 4 ][Ru II ( t Bubpy)(CN) 4 ] 2 ·8H 2 O (Ln = Pr, Nd, Sm, Eu) chain of {Ln 2 Ru 2 } molecular squares exhibits the orange emission of a typical metal-to-ligand charge transfer (MLCT) origin.…”

“…The intensity of this photoluminescence detected for the bulk solid sample, and the polymeric film, was reported to be strongly dependent on the presence of gaseous amine molecules, which additionally sensitize the Ru II -based emission. Therefore, this material found the analytical application as an efficient and sensitive chemodosimetric detector of biogenic amine odorants including histamine, putrescine, spermidine, and ammonia, indicating a great potential of the polycyanidometallate-based d–f coordination networks in chemical and biochemical sensing based on the spectrofluorometric detection [119]. …”

Spermine detection via metal-mediated ethynylarene ‘turn-on’ fluorescence signaling

“…Because such polyamines lack useful UV-Visible spectroscopic signatures themselves, systems capable of displaying spectroscopic changes in response to the presence of such analytes are necessary. Several examples of colorimetric and/or turn-on fluorescence sensors have been established, driven by the interactions of small molecule chromophores, [12–15] organic polymers, [16, 17] coordination compounds [18] and nanoparticles [19–21] with polyamine analytes of interest. Unfortunately, the majority of these methods have shown a limited ability to discriminate among spermine, spermidine, putrescine and cadaverine analytes.…”