In recent times, there was a rising curiosity in utilizing silver nanoclusters (Ag NCs), nanoscale silver particles composed of tens to lots of of atoms, throughout varied fields like materials science, chemistry, and biology. Ag NCs sometimes have sizes starting from 1-3 nm. Scientists have made important progress in creating and manipulating Ag NCs, resulting in the event of silver cluster-assembled supplies (SCAMs). SCAMs are light-emitting supplies made up of many interconnected Ag NCs, joined collectively by particular natural linker molecules known as “ligands.” What’s particular about them is their molecular-level structural designability and distinctive photophysical properties. Nonetheless, their widespread use has been restricted owing to their dissimilar structural structure when immersed in several solvents.
To deal with this drawback, a group of researchers from Tokyo College of Science (TUS), led by Professor Yuichi Negishi and together with Assistant Professor Saikat Das, lately developed two new (4.6)-connected three-dimensional luminescent SCAMs comprising an Ag12 cluster core related by quadridentate pyridine linkers — [Ag12(StBu)6(CF3COO)6(TPEPE)6]n, denoted as TUS 1 and [Ag12(StBu)6(CF3COO)6(TPVPE)6]n, denoted as TUS 2. “We’ve efficiently developed two silver -cluster-connected architectures with a brand new linkage construction, which may be utilized to environmental monitoring and evaluation,” explains Prof. Negishi. This examine was revealed within the journal Nanoscale on 26 June 2023.
The researchers synthesized the SCAMs utilizing the identical facile response methodology with the one distinction being the linker molecules. They mixed [AgStBu]n and CF3COOAg in an answer of acetonitrile and ethanol. The linker molecules TPEPE = 1,1,2,2-tetrakis(4-(pyridin-4-ylethynyl)phenyl)ethene and TPVPE = 1,1,2,2-tetrakis(4-((E)-2-(pyridin-4yl)vinyl)phenyl)ethene have been dissolved in separate chemical compounds, specifically tetrahydrofuran and dichloromethane, respectively. The steel answer was then added to the linker molecule answer and left to crystallize at the hours of darkness. After someday, yellow crystals shaped close to the junction of the 2 options, signifying the creation of the SCAMs.
The group carried out varied checks to look at the construction of the SCAMs. They discovered that TUS 1 had a rod-shaped construction, whereas TUS 2 had a block-shaped construction. In addition they examined the chemical stability of the supplies by immersing them in several solvents, and located that their crystal construction remained unchanged, highlighting their distinctive stability. Moreover, as a consequence of their distinctive fluorescence properties with a quantum yield of as much as 9.7% and stability in water, the group investigated the potential of SCAMs for detecting steel ions in aqueous options.
To their delight, each SCAMs have been extremely delicate to Fe3+ ions, which successfully quenched their fluorescence at room temperature, indicating the presence of Fe3+ ions. The detection limits of Fe3+ ions have been 0.05 and 0.86 nM L-1 for TUS 1 and TUS 2, respectively, akin to the usual values. Moreover, each SCAMs have been extremely selective in the direction of Fe3+ and weren’t affected by different frequent steel ions.
These outcomes counsel a possible utility of SCAMs in environmental monitoring, significantly in detecting Fe3+ ions in water. “The flexibility to hyperlink silver clusters by way of varied linkage modes can allow a bottom-up fabrication of supplies with varied physicochemical properties. Additional developments nanotechnology can thus permit us to manufacture supplies and units on a smaller scale, which is predicted to result in larger functionalities in supplies and units,” speculates Prof. Negishi.
