Facile one-pot synthesis of aliphatic thiol-derived nickel nanoclusters used for luminescent and dye degradation applications

Nickel nanoclusters (NiNCs) were successfully synthesised via a one-pot method, with 2,3-dimercaptosuccinic acid (DMSA) effectively stabilising the surface through interaction with Ni. Computational analysis of DMSA was performed using DFT at the B3LYP/3-21G level, confirming structural optimisation and stable geometry. The sulphur (–SH) and carboxyl groups exhibited strong electron-donating and withdrawing tendencies, with HOMO and LUMO values of 0.24915 and 0.18701, respectively, contributing to reactivity and complexation potential. UV-Vis absorption and fluorescence studies confirmed optical activity, with NiNCs displaying strong photoluminescence and a quantum yield of 48%, attributed to quantum confinement and surface passivation. Cytotoxicity studies revealed over 85% cell viability up to 100 nM, confirming excellent biocompatibility, while fluorescence microscopy showed minimal morphological alterations. TEM analysis indicated well-dispersed NiNCs under 5 nm. Furthermore, NiNCs demonstrated significant dye degradation efficiency within the visible absorbance range (2.3201×10 -3 to 6.0741×10 -6 μM), indicating strong photocatalytic potential. Overall, these findings highlight the dual role of aliphatic thiols in stabilising NiNCs for both bioimaging and dye degradation applications.