Haloperoxidase-mimicking CeO_2−xnanorods for the deactivation of human coronavirus OC43

Abstract

Schematic diagram of virucidal properties of haloperoxidase (HPO)-mimicking CeO2−x nanorods. CeO2−x nanorods catalysed the oxidative bromination of Br− and H2O2 to HOBr, which works as an antiseptic to kill viruses.

Insights on catalytic mechanism of CeO2 as multiple nanozymes

“…As intermediates, HOX can halogenate the Nacylhomoserine lactones, which are the important signaling molecules in bacterial quorum sensing [123]. Thus, the haloperoxidase can serve as the effective component of antifouling layers, especially for those against adhesions of marine microorganisms on the surface of marine equipment under the marine conditions [62,[123][124][125][126].…”

“…Although this study did not provide the information of structural defects, the enhanced abundance of oxygen vacancy and interfacial Ce 3+ due to the Bidoping might also contribute the improved catalytic haloperoxidases-like activity. Fabrication of CeO 2 nanorods embedded in the polyvinyl alcohol through electro-spinning method enhanced the wettability of nanozymes and improved mechanical stability of hybrids, leading to the increased haloperoxidases-like activity and stability to produce HOBr for combating bacterial adhesion [125].…”

Regulating the H2O2 Activation Pathway on a Well-Defined CeO2 Nanozyme Allows the Entire Steering of Its Specificity between Associated Enzymatic Reactions

“…The oxidation of Br – by OH radicals was ruled out due to a step uphill in the calculated Gibbs free energy. Although many following works can be found on this material recently, − the origin of its HPO activity is still unclear at present. Despite this, the implication from Tremel’s work to us is that the modulation of the H 2 O 2 activation pathway may allow the control of its reaction specificity among POD-/CAT-like and HPO-like activities.…”

“…Since then, many transition metal oxides (e.g., V 2 O 5 , Mn 3 O 4 , Co 3 O 4 , Cu 2 O, CeO 2 , etc.) with switchable oxidation states have been reported to mimic not only HRP − but also other H 2 O 2 -associated oxidoreductases such as catalase − and haloperoxidase. − In the literature, peroxidase (POD)-like activity is often attributed to the conversion of H 2 O 2 to OH radicals (Scheme a­(i)), while catalase (CAT)-like activity decomposes H 2 O 2 to H 2 O and O 2 (Scheme a­(ii)). Haloperoxidase (HPO)-like activity, on the other hand, catalyzes the oxidation of halides with H 2 O 2 to hypohalous acids (e.g., Br – to HOBr, − Scheme a­(iii)).…”

A cascade nanozyme with antimicrobial effects against nontypeable Haemophilus influenzae

“…Nanomaterials, such as iron nanoparticles, silver nanoparticles, and cerium nanoparticles, with their demonstrated enzyme-like activities (e.g., peroxidase-like activity) have been leveraged as antimicrobials with minimal resistance identified thus far. [20][21][22][23][24][25] Nanozymes tend to have improved stability and catalytic efficiency in a broader range of temperature and pH with relatively low cost of production compared to natural enzymes. 26 Nevertheless, although nanozymes have shown excellent potential in biomedical and environmental applications, 27,28 their use in the treatment of OM and other infectious diseases has been limited.…”