A novel method has been developed to immobilize tyrosinase onto the surface of boron-doped diamond (BDD) electrode. The hydrogen-terminated BDD (HBDD) surface was first functionalized by photochemically linking vinyl groups of allylamine, producing covalently linked amine-terminated active BDD (ABDD) surface. Then the tyrosinase was immobilized onto the ABDD surface by carbodiimide coupling reaction. The amperometric response was measured as a function of concentration of phenolic compounds in 0.1M phosphate buffer solution (pH 6.5). The tyrosinase-modified ABDD electrode gave a linear response range of 1-175, 1-200 and 1-200 microM and sensitivity of 80.0, 181.4 and 110.0 mA M(-1)cm(-2) for phenol, p-cresol, 4-chlorophenol, respectively. Moreover, selective detection of dopamine (DA) in the presence of ascorbic acid (AA) has been demonstrated with the tyrosinase-modified ABDD electrode. Linearity was observed within the range of 5-120 microM. The above enzyme electrode could maintain 90% of its original activity after intermittent use for 1 month when storing in a dry state at 4 degrees C.
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http://dx.doi.org/10.1016/j.bios.2006.03.001 | DOI Listing |
Macromol Biosci
February 2025
Department of Chemistry, Pusan National University, Busan, 46241, Republic of Korea.
In this study, a substrate-independent maleimide film is developed that can be formed under mild aqueous conditions (pH 7.4), and which allows rapid and efficient external thiol immobilization onto the coated surfaces. For the coating block, tyrosine-conjugated maleimide (Tyr-Mal) containing a phenolic amine moiety is prepared as a substrate-independent dormant coating precursor, wherein the maleimide component permits a rapid Michael addition reaction with the thiol moiety of interest.
View Article and Find Full Text PDFFood Chem
May 2025
School of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China. Electronic address:
To achieve the biotransformation of cellulose into gluconic acid, a multi-enzyme reactor comprising cellulase, glucose oxidase, and catalase was constructed through artificial antibody-antigen-directed immobilization. Catechol was used as a template to prepare artificial antibodies, which were then used to modify the enzymes through a Schiff base reaction to form artificial antigens. The artificial antibody and antigen were subsequently assembled via affinity recognition to immobilize the enzymes.
View Article and Find Full Text PDFInt J Biol Macromol
March 2025
School of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China. Electronic address:
Accurate, specific, and cost-effective detection of toxic cyanogenic glycosides is crucial for ensuring biological health and food safety. In this study, a novel biosensor based on co-immobilized multi-enzyme system was constructed by artificial antibody-antigen-directed immobilization for the colorimetric detection of amygdalin through a cascade reaction catalyzed by β-glucosidase, glucose oxidase, and horseradish peroxidase. Artificial antibodies and antigens were prepared using catechol and 3,4-dihydroxybenzaldehyde, respectively, to generate mutual affinity recognition ability for enzyme immobilization.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Lab of Applied Biocatalysis, National Engineering Research Center of Wheat and Corn Further Processing, School of Food Science and Engineering, South China University of Technology, No. 381 Wushan Road, Guangzhou 510640, Guangdong China.
Biomineralization of enzymes inside rigid metal-organic frameworks (MOFs) is appealing due to its biocompatibility and simplicity. However, this strategy has hitherto been limited to microporous MOFs, leading to low apparent enzymatic activity. In this study, polysaccharide sodium alginate is introduced during the biomineralization of enzymes in zeolitic imidazolate frameworks (ZIFs) to competitively coordinate with metal ions, which endows the encapsulated enzyme with a 7-fold higher activity than that in microporous ZIFs.
View Article and Find Full Text PDFFood Res Int
January 2025
College of Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, China.
The dried capitulum of chrysanthemums is a traditional material in scented tea, and the kill-green process is a critical step in determining their quality. However, the changes in the physicochemical properties during kill-green and the mechanisms by which these changes affect drying characteristics, metabolic components, and aroma profiles remain unclear. Therefore, this study investigated the changes in water status, polyphenol oxidase and peroxidase activities, and microstructure during high-humidity air impingement kill-green (HHAIK) and steam kill-green (SK), and their effects on drying behavior, color, phytochemicals, and volatile profile of dried chrysanthemums.
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