High catalytic activity and substrate specificity make enzymes a rich source of inspiration for catalyst development.Co-opting the advantages of natural materials while tuning them to a modified form and purpose,howev...High catalytic activity and substrate specificity make enzymes a rich source of inspiration for catalyst development.Co-opting the advantages of natural materials while tuning them to a modified form and purpose,however,is not a straightforward synthetic task.Polymerization of L-3,4-dihydroxyphenylalanine(L-DOPA)results in amorphous polymer nanoparticles that are similar in many ways to natural eumelanin.Herein,the authors introduce mesoporosity and iron ion chelation to synthesize a variant of the L-DOPA polymer with high peroxidase-like activity.Our results indicate catalytic reaction with peroxide under mildly acidic conditions(pH 5.4 and 6)with a greater maximum reaction velocity(Vmax)than horseradish peroxidase(HRP)at optimal pH 3.5–4.5.Comparison between Fe(Ⅲ)and Fe(Ⅱ)loading indicates that either can be used as a starting point to trigger reactivity,though Fe(Ⅱ)loading leads to materials with twice the Vmax of the Fe(Ⅲ)-loaded sample.The lack of catalyst degradation despite the redox changes and presence of radical species is consistent with the robust nature and redox versatility of polydopamine-based materials and demonstrates strong potential as a versatile redox-catalysis platform.展开更多
基金support from the Air Force of Scientific Research MURI(grant no.FA9550-18-1-0142)supported by the National Science Foundation(grant no.ECCS-1542148)M.K.is supported by the Department of Defense(DoD)through the National Defense Science and Engineering Graduate(NDSEG)Fellowship Program.
文摘High catalytic activity and substrate specificity make enzymes a rich source of inspiration for catalyst development.Co-opting the advantages of natural materials while tuning them to a modified form and purpose,however,is not a straightforward synthetic task.Polymerization of L-3,4-dihydroxyphenylalanine(L-DOPA)results in amorphous polymer nanoparticles that are similar in many ways to natural eumelanin.Herein,the authors introduce mesoporosity and iron ion chelation to synthesize a variant of the L-DOPA polymer with high peroxidase-like activity.Our results indicate catalytic reaction with peroxide under mildly acidic conditions(pH 5.4 and 6)with a greater maximum reaction velocity(Vmax)than horseradish peroxidase(HRP)at optimal pH 3.5–4.5.Comparison between Fe(Ⅲ)and Fe(Ⅱ)loading indicates that either can be used as a starting point to trigger reactivity,though Fe(Ⅱ)loading leads to materials with twice the Vmax of the Fe(Ⅲ)-loaded sample.The lack of catalyst degradation despite the redox changes and presence of radical species is consistent with the robust nature and redox versatility of polydopamine-based materials and demonstrates strong potential as a versatile redox-catalysis platform.
