Removal of Diclofenac, Paracetamol, and Carbamazepine from Model Aqueous Solutions by Magnetic Sol–Gel Encapsulated Horseradish Peroxidase and Lignin Peroxidase Composites

Abstract

Sustainable and green synthesis of nanocomposites for degradation of pharmaceuticals was developed via immobilization and stabilization of the biological strong oxidizing agents, peroxidase enzymes, on a solid support. Sol–gel encapsulated enzyme composites were characterized using electron microscopy (TEM, SEM), atomic force microscopy, FTIR spectroscopy, and thermogravimetric analysis. Horseradish peroxidase (HRP) and lignin peroxidase (LiP) were adsorbed onto magnetite nanoparticles and sol–gel encapsulated in a surface silica layer. Encapsulation enhanced the stability of the biocatalysts over time and thermal stability. The biocatalysts showed appreciable selectivity in oxidation of the organic drinking water pollutants diclofenac, carbamazepine, and paracetamol with improved activity being pharmaceutical specific for each enzyme. In particular, sol–gel encapsulated LiP- and HRP-based nanocomposites were active over 20 consecutive cycles for 20 days at 55 °C (24 h/cycle). The stability of the sol–gel encapsulated catalysts in acidic medium was also improved compared to native enzymes. Carbamazepine and diclofenac were degraded to 68% and 64% by sol–gel LiP composites respectively at pH 5 under elevated temperature. Total destruction of carbamazepine and diclofenac was achieved at pH 3 (55 °C) within 3 days, in the case of both immobilized HRP and LiP. Using NMR spectroscopy, characterization of the drug decomposition products, and decomposition pathways by the peroxidase enzymes suggested.

Magnetic Nanoparticle-Containing Supports as Carriers of Immobilized Enzymes: Key Factors Influencing the Biocatalyst Performance

“…The magnetic recovery of immobilized enzymes is normally realized by tethering enzymes to magnetic NPs via some linkers such as polymers, difunctional molecules, etc. [ 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. To create an appreciable magnetic moment for a successful separation, magnetic NPs are often organized into clusters [ 34 , 38 ], imbedded in gels [ 36 ], other polymer or inorganic matrices [ 13 , 39 , 40 , 41 ], or self-assembled into larger structures [ 42 , 43 ].…”

“…[ 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. To create an appreciable magnetic moment for a successful separation, magnetic NPs are often organized into clusters [ 34 , 38 ], imbedded in gels [ 36 ], other polymer or inorganic matrices [ 13 , 39 , 40 , 41 ], or self-assembled into larger structures [ 42 , 43 ]. This creates interparticle interactions and increases magnetic attraction between magnetic NPs and an external magnetic field.…”

“…The magnetic recovery of immobilized enzymes is normally realized by tethering enzymes to magnetic NPs via some linkers such as polymers, difunctional molecules, etc. [31][32][33][34][35][36][37].…”

“…Clustering of the NPs surrounded by the thermoresponsive polymer allows for easy magnetic separation. [31][32][33][34][35][36][37]. To create an appreciable magnetic moment for a successful s NPs are often organized into clusters [34,38], imbedded in gels [36], o organic matrices [13,[39][40][41], or self-assembled into larger structures interparticle interactions and increases magnetic attraction between m external magnetic field.…”

Degradation of Bisphenol a Using Horseradish Peroxidase Immobilized on Fe-based MOFs

“…Horseradish peroxidase (HRP) is a heme protein with an iron porphyrin active center, which can oxidize and degrade bisphenol A in the presence of H 2 O 2 . After oxidized to free radicals, the substrate molecules can be rearranged and coupled to form corresponding polymers and other compounds, which are non-toxic and can be easily removed from water (Pylypchuk et al 2020). Nevertheless, the free HRP has many drawbacks including poor thermal and storage stability, high cost for no reusability and recyclability.…”