Zr-MOF nanocolloids prepared by pulsed laser ablation in water for tyrosine electrochemical sensing

This work presents the synthesis of contaminant-free Zr-MOF nanocolloids via pulsed laser ablation in liquids, a green and by-product-free top-down approach. A focused picosecond laser beam was employed to ablate a UiO-67 MOF target immersed in deionized water, yielding well-dispersed nanostructures with diameters ranging from 20 to 100 nm. For comparison, the effects of direct laser irradiation on dispersed UiO-67 powders were also investigated. Scanning-Transmission Electron Microscopy revealed a distinct morphological reorganization of the nanostructures upon laser processing. The ablation products were comprehensively characterized using Dynamic Light Scattering, optical spectroscopy, and X-ray photoelectron spectroscopy (XPS), the latter indicating significant surface stoichiometric modifications consistent with changes in the zirconium coordination environment. Finally, the electrochemical sensing performance of the colloids was evaluated using D-tyrosine as a model analyte. The PLAL-synthesized samples exhibited outstanding sensitivity, a low detection limit of 0.10 μM in phosphate-buffered saline, and excellent selectivity toward D-tyrosine even in the presence of common interferents like dopamine and uric acid, as well as in complex media.