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Size‐Dependent Photoluminescence from Thiolate‐Protected Water‐Soluble Cobalt Nanoclusters
Author(s) -
Ramadurai Murugan,
Vinitha Packirisamy,
Prabhu Pandurangan,
Komathi Shanmugam,
Suresh Babu Rajendran
Publication year - 2020
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201903751
Subject(s) - nanoclusters , luminescence , photoluminescence , quantum yield , materials science , ligand (biochemistry) , metal , photochemistry , nanoparticle , fluorescence , cobalt , quantum dot , nanotechnology , chemistry , optoelectronics , physics , optics , metallurgy , biochemistry , receptor
The luminescence property of highly oxidative transition metal nanostructures using Co, Ni and Cu are being challenging. Due to their high susceptibility for oxidation and non‐existence of appropriate synthesis methodologies and lack of efficient mechanism to confirm their luminescence properties. To overcome these shortcomings, herein we report a new synthesis strategy to develop a novel tripeptide thiolate ligand i. e., glutathione (GS) protected ultrasmall water‐soluble cobalt nanoclusters, Co n (GS) m. As achieved Co n (GS) m clusters were isolated from the crude CoGS using polyacrylamide gel electrophoresis (PAGE) technique. The PAGE separation for the crude CoGS sample resulted in three bands of varying sizes i. e., 2–5 nm (band 1), 6–18 nm (band 2) and 13–28 nm (band 3), which exhibits size‐dependent luminescence with quantum yields of 10 %, 7.5 % and 5.8 % respectively. Among them, the maximum quantum yield for the ultrasmall Co n (GS) m nanoclusters from the band 1 exhibits a blue emission which could be as result of synergetic behaviour from the aggregation induced emission (AIE) and ligand‐metal‐metal charge transfer (LMMCT) relaxations offered by the triplet state of Co n (GS) m nanoclusters. This significant results for the water‐soluble, highly robust and luminescent Co n (GS) m nanoclusters confirm their potential ability to act as an alternative to expensive metal nanoparticles and conventional fluorescent materials for the technological and bioimaging applications.