LAUSR

New CdS NPs decorated with 2-thiobenzimidazole (TB) were synthesized as chemo-sensors for selective recognition of potassium ions. The results show that CdS–TB NPs are sensitive and selectively detect K+ ions, finding that there is no interference from other metal ions (Mn2+, Mg2+, Cu2+, Co2+, Cr3+, Fe3+, Ni2+, Zn2+, Sr2+, Ag+, Sm3+, Al3+, Cd2+, Ba2+, Na+), and the detection limit was as low as 0.008 mM. In antibacterial studies, CdS–TB NPs exhibit non-toxicity towards bacterial systems, suggesting that the decoration of TB molecules reduces the toxicity of CdS NPs. In order to understand the binding nature of TB molecules with CdS, the structural and electronic properties of different CdS clusters [(CdS)n, n = 1–16] were analyzed by Density Functional Theory (DFT) before and after their interaction with TB, and the molecular orbitals and density of states were used to describe the nature of the bonding between metal oxide clusters and TB molecules.Graphical Abstract