Strategy for the Fabrication of a Zeolite Imidazole Framework-Based Hybrid Nanomaterial Applied in the Sensing Field: Deep Eutectic Solvent as a Shape-Controller of Gold Nanostars

Zeolite imidazole frameworks (ZIFs) hybridized with localized surface plasmon resonance nanoparticles have been focused ubiquitously on optimizing fabrication processes for optical sensing applications to obtain well-performed sensitivity. In this study, we propose a novel strategy of utilizing a deep eutectic solvent to assist the formation of a hybrid nanostructure containing ZIF-8 and gold nanostars without any seed-mediated or developing steps. Through several characterization techniques, Z8AuD hybrid materials are proven to be successfully synthesized, in which 80-100 nm gold nanostars bind to 100-200 nm ZIF-8. We also demonstrate the ultrasensitivity of Z8AuD via surface-enhanced Raman spectroscopy and optical fiber sensing. As a result, methylene blue and thiram are detectable down to 6.74 and 0.24 nM using Raman spectroscopy, as well as 0.12 and 0.098 pM thanks to the optical fiber sensor, respectively. These works aim at providing another aspect of hybrid nanomaterial synthesis based on deep eutectic solvents, generally proving considerable roles and potential of deep eutectic solvents in the sensing field.