Efficient Electroenzymatic Cascade Catalysis for Ortho-Selective Chlorination of Phenol

The integration of enzymatic catalysis and electrocatalysis is promising for developing new green techniques for chemical production; however, how to coordinate the two processes for one-pot cascade reactions is a challenge. In this work, the electrocatalytic reduction of O2 to H2O2 by a reduced graphene oxide (rGO)/polyethylenimine (PEI) composite to initiate an enzymatic reaction by ionic liquid modified chloroperoxidase (CPO-ILEMB) is presented. The whole cascade process is very efficient due to the four strategies, including avoiding the inactivation of CPO through the competitive reaction of oxidant (H2O2), utilizing nanoproximity effects to construct substrate diffusion channels, fine-tuning the microenvironment of the enzymatic active site by ILEMB to increase the electron transfer efficiency as well as enhance the stability, and improving the selectivity of the 2e-ORR (oxidation reduction reaction) of rGO by PEI. The cascade efficiency is enhanced 5.5 times compared to manually adding H2O2, and 2.3 times compared to free CPO. Moreover, the rapid generation of intermediate (compounds I and X) and the orientation of substrate lead to ortho-selectivity of phenol chlorination

Efficient Electroenzymatic Cascade Catalysis for Ortho-Selective Chlorination of Phenol

The integration of enzymatic catalysis and electrocatalysis is promising for developing new green techniques for chemical production; however, how to coordinate the two processes for one-pot cascade reactions is a challenge. In this work, the electrocatalytic reduction of O2 to H2O2 by a reduced graphene oxide (rGO)/polyethylenimine (PEI) composite to initiate an enzymatic reaction by ionic liquid modified chloroperoxidase (CPO-ILEMB) is presented. The whole cascade process is very efficient due to the four strategies, including avoiding the inactivation of CPO through the competitive reaction of oxidant (H2O2), utilizing nanoproximity effects to construct substrate diffusion channels, fine-tuning the microenvironment of the enzymatic active site by ILEMB to increase the electron transfer efficiency as well as enhance the stability, and improving the selectivity of the 2e-ORR (oxidation reduction reaction) of rGO by PEI. The cascade efficiency is enhanced 5.5 times compared to manually adding H2O2, and 2.3 times compared to free CPO. Moreover, the rapid generation of intermediate (compounds I and X) and the orientation of substrate lead to ortho-selectivity of phenol chlorination

Efficient Electroenzymatic Cascade Catalysis for Ortho-Selective Chlorination of Phenol

The integration of enzymatic catalysis and electrocatalysis is promising for developing new green techniques for chemical production; however, how to coordinate the two processes for one-pot cascade reactions is a challenge. In this work, the electrocatalytic reduction of O2 to H2O2 by a reduced graphene oxide (rGO)/polyethylenimine (PEI) composite to initiate an enzymatic reaction by ionic liquid modified chloroperoxidase (CPO-ILEMB) is presented. The whole cascade process is very efficient due to the four strategies, including avoiding the inactivation of CPO through the competitive reaction of oxidant (H2O2), utilizing nanoproximity effects to construct substrate diffusion channels, fine-tuning the microenvironment of the enzymatic active site by ILEMB to increase the electron transfer efficiency as well as enhance the stability, and improving the selectivity of the 2e-ORR (oxidation reduction reaction) of rGO by PEI. The cascade efficiency is enhanced 5.5 times compared to manually adding H2O2, and 2.3 times compared to free CPO. Moreover, the rapid generation of intermediate (compounds I and X) and the orientation of substrate lead to ortho-selectivity of phenol chlorination

Representative histological images of the Ca(OH)₂ and DBM groups (x100 magnification, H&E staining).

<p>A: The blank control group. Pulp morphology was normal. B-F: Ca(OH)₂ group (1, 3, 7, 14, and 28 days). G-K: DBM group (1, 3, 7, 14, and 28 days). Inflammatory reactions began from 1 day and continued to exist through the observation period. Reparative dentin formation could be observed in both groups on 28 days, and the DBM group showed more regular and thinner reparative dentin. Arrowheads indicate inflammatory reaction. RD means reparative dentin.</p

Inflammatory Cell Infiltration (ICI).

<p>Inflammatory Cell Infiltration (ICI).</p

Reparative Dentin Formation (RDF).

<p>Reparative Dentin Formation (RDF).</p

Immunohistochemical expression of DSP.

<p>(A): Representative immunohistochemical images of the blank control group, the Ca(OH)₂ group, and the DBM group. a: The blank control group. Pulp morphology was normal. b- f: Ca(OH)₂ group (1, 3, 7, 14, 28 days). g- k: DBM group (1, 3, 7, 14, 28 days). (B): Mean IOD value of DSP. *means significant differences.</p

Pulp Tissue Disorganization (PTD).

<p>Pulp Tissue Disorganization (PTD).</p

Immunohistochemical expression of COL I.

<p>(A): Representative immunohistochemical images of the blank control group, the Ca(OH)₂ group, and the DBM group. a: The blank control group. Pulp morphology was normal. b- f: Ca(OH)₂ group (1, 3, 7, 14, 28 days). g- k: DBM group (1, 3, 7, 14, 28 days). (B): Mean IOD value of COL I. *means significant differences.</p

Results of the histopathological evaluation.

<p>ICI: Inflammatory cell infiltration, PTD: Pulp tissue disorganization, RDF: Reparative dentin formation.</p