Emerging investigator series: enhanced peroxidase-like activity and improved antibacterial performance of palladium nanosheets by an alginate-corona. Issue 12 (28th October 2021)

• Record Type: Journal Article
• Authors: Ma, Minghao; Wang, Ruixia; Xu, Lining; Du, Jingjing; Xu, Ming; Liu, Sijin
• Is Part Of: Environmental science. Volume 8:Issue 12(2021)
• Page Start: 3511
• Page End: 3523
• Publication Date: 2021-10-28
• Subjects: Environmental sciences -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/d1en00485a
• Languages: English
• ISSNs: 2051-8153

Abstract

Abstract : The formation of an alginate corona on the surface of Pd nanosheets can boost their peroxidase-like activity, giving rise to the fast generation of hydroxyl radicals and the enhancement of antibacterial activity. Abstract : Once released into the natural environment, ecological macromolecules can rapidly form a coronal architecture on the surface of engineered nanomaterials, altering their intrinsic physicochemical properties as well as nano–bio interactions. Palladium (Pd)-based nanomaterials attract an increasing attention in the fields of environmental science, due to their remarkable catalytic activity. However, the current understanding of the interplay between Pd-based nanomaterials and ecological macromolecules remains limited. In this study, taking two-dimensional Pd nanosheets (Pd NSs) as a representative, we characterized the corona formation of four ecological substances ( i.e. humic acid, fulvic acid, alginate and Suwannee River natural organic matter) on the Pd NS surface, and assessed their influence on the peroxidase-like activity of Pd NSs. Our findings showed that the overcoating of alginate-corona on Pd NS surface could significantly enhance the peroxidase-like activity of Pd NSs, but not the other three, thus leading to the fast generation of hydroxyl radicals (˙HO). Moreover, the antibacterial activity of the pristine and alginate-coronated Pd NSs was respectively examined with both Gram-positive bacteria ( Staphylococcus aureus, Bacillus cereus ) and Gram-negative bacteria ( Escherichia coli, Pseudomonas aeruginosa ). The growth inhibition assay yielded the half maximal inhibitory concentration (IC50 ) values of the pristine Pd NSs ranging from 4.6 to 12.1 μg mL −1 and the alginate-coronated Pd NSs ranging from 2.0 to 6.7 μg mL −1, respectively. The higher toxicity of the alginate-coronated Pd NSs was demonstrated to be attributed to the formation of alginate-corona and enhanced ˙HO radical production ability, giving rise to bacterial membrane damage, oxidative stress, biofilm inhibition and cell death. Our findings may facilitate an in-depth understanding of the crucial role of environmental corona in the exotoxicological risks and antibacterial performance of engineered nanomaterials.