Benzimidazole-modified organosilane functionalized silica nanoparticles as a ‘turn-off’ fluorescent probe for highly selective Cu2+ ion detection: unravelling logic gate behaviour and molecular docking studies

Exploring the development of fluorescent probes functionalized with triazoles derived from click chemistry is particularly intriguing due to their significant potential for expanding their applications in fluorescence analysis and medicine. In this study, we have successfully engineered a sensor by immobilizing a benzimidazole organosilane (5) onto the surface of composite silica nanoparticles using the azide–alkyne cycloaddition process. This innovative approach offers a straightforward, rapid, highly sensitive, selective, and accurate detection method with a low detection limit, especially in terms of its remarkable selectivity for Cu2+ over other biologically and environmentally relevant ions. Our findings demonstrate that the H-NP probe outperforms probe 5, as evidenced by its lower limit of detection and a higher binding association constant for Cu2+ ions. Furthermore, we conducted molecular docking studies of compound 5 within the binding site of Staphylococcus aureus (PDB: 5M1A) to investigate its biological activity and its potential as an inhibitor of Staphylococcus aureus.