Production of flower‐shaped nanobiocatalysts from green tea and investigation of their peroxidase mimicking activity on the polymerization of phenol derivatives

Abstract

Enzyme catalyzed reactions are known to be environmental friendly and easy method for many applications. However, utilization of enzymes in a variety of reactions is strictly limited due to their high cost, instability in aqueous solutions, denaturation in organic solvents and high temperatures. For this reason, it is important to discover new generation catalyst systems indicating enzyme‐like catalytic activity. Here, we report hybrid organic–inorganic flower‐shaped green tea‐Cu2+ nanobiocatalyst synthesized from green tea extract as an organic component and copper (II) ions (Cu2+) as inorganic component. The effect of the peroxidase‐mimicking activity of green tea‐Cu2+ nanobiocatalyst was investigated on the polymerization of phenol and derivatives (guaiacol and salicylic acid) through Fenton‐like reaction mechanism. Obtained successful outcomes showed that the synthesized nanobiocatalyst showed very high catalytic activity upon polymerization of phenol and guaiacol. The slight solubility of salicylic acid in water limited to achieve its polymerization under‐performed reaction conditions. The yields and molecular weights of the obtained polymers were found to be quite high. While free peroxidase enzymes like horseradish peroxidase (HRP) enzyme loses its catalytic activity at 60°C and above temperatures, green tea‐Cu2+ nanobiocatalyst exhibited very high catalytic activity upon polymerization reactions even at 60°C reaction temperature. This outcome provides significant advantages in some reactions requiring high temperatures. In order to understand the origin of the catalytic activity of the green tea‐Cu2+ nanoflowers, similar biocatalysts were also synthesized from caffeine and catechin alkaloids which are the active components of green tea. Caffeine‐Cu2+ and catechine‐Cu2+ nanobiocatalysts also exhibited quite high catalytic activity toward polymerization of phenol and derivatives. We suggest that green tea‐Cu2+ and similar types of nanobiocatalysts may expand their utilization in polymer chemistry as promising catalytic agents for radicalic polymerizations.

Green nanobiocatalysts: enhancing enzyme immobilization for industrial and biomedical applications

“…In the final step, the petals stick together to form a nanoflower ( Celik et al, 2018 ). Organic–inorganic hybrid nanoflowers in the form of flowers have the potential to be employed in a variety of applications such as industrial biocatalysts, biosensors, bioanalytical instruments, biomedicine, and biofuel cells ( Yilmaz et al, 2022 ; Kalayci et al, 2024 ; Aslan et al, 2024 ).…”

“…Compared with chemical processes, which are carried out under extremely harsh conditions and result in unwanted side by-products, biocatalysts demonstrate remarkable selectivity and specificity for their substrates under moderate conditions ( Singh et al, 2023 ). The use of soluble enzymes as environmentally friendly catalysts may be impeded by their limitations, including inability to be reused, increased susceptibility to various denaturing agents, elevated cost, instability in large-scale processing, conformational changes, lack of reusability, and inapplicability in fixed-bed reactors ( Dadi et al, 2023b ; Mohidem et al, 2023 ; Kalayci et al, 2024 ). The production of NBCs involves the integration of enzyme molecules onto carriers composed of nanomaterials to enhance the specific chemical kinetics and substrate selectivity ( Oke et al, 2023 ).…”

Immobilized Dipeptidase in Manganese Ion-Loaded Polyethylenimine-Induced Calcium Phosphate Nanocrystals for Carnosine Synthesis

“…20,21 In addition, some non-protein molecules could also form organic− inorganic hybrid nanoflowers with metal ions, which showed peroxidase mimetic activity through the Fenton-like mechanism and could serve as promising nanobiocatalysts for free radical polymerization. 22 However, the long synthesis time, low synthetic yield, and poor structural stability of conventional organic−inorganic hybrid nanomaterials have limited their application in industrial production. 23,24 To overcome these drawbacks, some researchers have exploited the property that some biomacromolecules can reduce the nucleation barrier of crystals and thus to accelerate the nucleation and growth of inorganic minerals to develop a rapid synthesis scheme of organic−inorganic hybrid nanoflowers, and demonstrated their great potential for biocatalyst applications.…”

“…Enzyme immobilization is usually used to improve enzyme activity and stability, in which the structure of the enzyme is relatively fixed and the enzyme is protected from denaturation by the carrier. − Organic–inorganic hybrid nanomaterials, metal–organic frameworks, covalent organic frameworks, and mesoporous silica are important carriers for enzyme immobilization. − Among them, the organic–inorganic hybrid nanoflower has the advantages of high specific surface area and easy synthesis. , Due to the activation of the enzyme by metal ions and restriction of nanoflowers, the activity and stability of enzyme-inorganic hybrid nanoflowers could be improved as compared with free enzymes. , In addition, some non-protein molecules could also form organic–inorganic hybrid nanoflowers with metal ions, which showed peroxidase mimetic activity through the Fenton-like mechanism and could serve as promising nanobiocatalysts for free radical polymerization . However, the long synthesis time, low synthetic yield, and poor structural stability of conventional organic–inorganic hybrid nanomaterials have limited their application in industrial production. , To overcome these drawbacks, some researchers have exploited the property that some biomacromolecules can reduce the nucleation barrier of crystals and thus to accelerate the nucleation and growth of inorganic minerals to develop a rapid synthesis scheme of organic–inorganic hybrid nanoflowers, and demonstrated their great potential for biocatalyst applications. , Among them, biomacromolecules rich in carboxyl, hydroxyl, and amino groups are the most significant.…”