Temperature-induced formation of Pd nanoparticles in heterogeneous nanobiohybrids

• Published in: Nanoscale Advances
• Main Authors: Losada-Garcia, Noelia, Santos, A. Sofia, Marques, M. Manuel B., Palomo, Jose M.
• Other Authors: LAQV@REQUIMTE, DQ - Departamento de Química
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2023
• Subjects: Bioengineering; Atomic and Molecular Physics; and Optics; Chemistry(all); Materials Science(all); Engineering(all); Antarc*; Antarctica
• Online Access: http://hdl.handle.net/10362/149850; https://doi.org/10.1039/d2na00742h

This work was supported by the Spanish Government, the Spanish National Research Council (CSIC). We also thank Dr Martinez from Novozymes. Publisher Copyright: © 2023 RSC. The effect of the temperature in the synthesis of Pd nanoparticles in the metal-enzyme biohybrids is evaluated. The effect on the formation, size, and morphology of nanoparticles was evaluated using C. antarctica B lipase as the protein scaffold. XRD analyses confirmed the formation of crystalline Pd(0) as the metal species in all cases. TEM analyses revealed spherical crystalline nanoparticles with average diameter size from 2 nm at 4 °C synthesis to 10 nm obtained at 50 °C synthesis. The thermal phenomenon was also critical in the final hybrid formation using more complex enzymes, where the relation of the protein structure and temperature and the influence of the latter has been demonstrated to be critical in the reducing efficiency of the enzyme in the final Pd nanoparticle formation, in the metal species, or even in the final size of the nanoparticles. Different Pd biohybrids were evaluated as catalysts in the C-H activation of protected l-tryptophan under mild conditions. Pd@CALB4 showed the best results, with >99% conversion for C-2 arylation in methanol at room temperature with a TOF value of 64 min−1, being 2 or 4 times higher than that of the other synthesized hybrids. This catalyst showed a very high stability and recyclability, maintaining >95% activity after three cycles of use. publishersversion published