Modulating the size and photoluminescence of a copper nanocluster via metal-organic frameworks encapsulating strategy for fluorescence sensing

Modulating the Optical Properties of Cationic Surfactant Cetylpyridinium Chloride and Hydrazine Mediated Copper Nanoclusters

This study investigates the modulations in the optical properties of cationic surfactant cetylpyridinium chloride (CPC) and hydrazine-mediated copper nanoclusters (CuNCs). By employing a bottom-up approach, we demonstrate the formation of blue-emitting CuNCs facilitated by CPC and hydrazine, where hydrazine acts both as a reducing and stabilizing agent. The optical properties of the CuNCs were systematically tuned by varying the chain length of the diamine, resulting in emissions ranging from blue to yellow. Comprehensive characterization using spectroscopic and microscopic techniques confirmed the successful formation of CuNCs and elucidated the roles of CPC and hydrazine in their preparation. Control experiments highlighted the critical role of the pyridinium moiety and hydrophobic chain of CPC in enhancing the photoluminescence properties of the CuNCs. This work provides new insights into the design of stable, highly luminescent CuNCs for potential applications in optoelectronics and bioimaging.

Enzyme-free ratiometric fluorescence and colorimetric dual-signal determination of glyphosate based on copper nanoclusters (ZIF/CuNCs) combined with blue carbon dots (bCDs)

A novel ratio fluorescent and colorimetric dual-signal sensing platform for detecting glyphosate based on blue carbon dots (bCDs) combined with ZIF/CuNCs nanomaterials that encapsulate copper nanoclusters (CuNCs) in a metal-organic framework (MOF). In principle, the immobilization of Cu2+ in ZIF/CuNCs results in complexation with imidazole in ZIF, leading to fluorescence quenching of ZIF/CuNCs, while the reference fluorophore bCDs remains unaffected. In addition, the colorimetric sensing strategy was based on the efficient peroxidase-like activity of bCDs binding to Cu2+, catalyzing H2O2 to generate OH. Under this condition, TMB could be oxidized to form blue oxTMB. However, when glyphosate was involved in the system, the fluorescence of ZIF/CuNCs was restored upon due to the strong chelation between Cu2+ and glyphosate, while the peroxidase-like activity of bCDs/Cu2+ decreased and resulted in the generation of fewer oxTMB, accompanied by a lighter blue color. The sensing platform was successfully applied to the determination of glyphosate in real samples of lake water and cabbage, demonstrating reliable and sensitive performance in practical applications.