Direct electrochemistry of horseradish peroxidase immobilized on electrografted 4-ethynylphenyl film via click chemistry

• Published in: Analytica chimica acta Vol. 697; no. 1; pp. 27 - 31
• Main Authors: Ran, Qin, Peng, Ru, Liang, Cong, Ye, Siqiu, Xian, Yuezhong, Zhang, Wenjing, Jin, Litong
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 04.07.2011; Elsevier
• Subjects: Adsorption; Analytical chemistry; Biocatalysis; Biological and medical sciences; Biosensor; Biosensors; Biotechnology; Chemistry; Click Chemistry; Covalence; Diazonium Compounds - chemistry; Diazonium salts; Direct electron transfer; Electrochemical methods; Electrochemistry - methods; Electrodes; Electron Transport; Enzymes, Immobilized - chemistry; Enzymes, Immobilized - metabolism; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Gold - chemistry; Horseradish peroxidase; Horseradish Peroxidase - chemistry; Horseradish Peroxidase - metabolism; Hydrogen Peroxide - analysis; Hydrogen Peroxide - metabolism; Infrared; Mathematical analysis; Methods. Procedures. Technologies; Models, Molecular; Peroxidase; Protein Conformation; Reduction; Reflection; Spectrometric and optical methods; Surface chemistry; Various methods and equipments; Horseradish peroxidase; Direct electron transfer; Click chemistry; Diazonium salts; Biosensor; Enzyme; Electrochemical method; Immobilization; Electron transfer; Chemical sensor; Protein; Infrared spectrometry; Reflection spectrometry; Electrocatalysis; Absorption spectrometry; Chemistry; Reduction; Peroxidases; Thin layer electrode; Process modification; Peroxidase; Oxidoreductases; Diazonium compounds
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2011.04.035

Hydrogen peroxide biosensor was developed based on electrochemically assisted aryldiazonium salt chemistry and click chemistry. [Display omitted] ► A simple, versatile two-step approach, which is based on electrochemically assisted aryldiazonium salt chemistry and Cu(I)-catalyzed azide alkyne cycloaddition (CuAAC) reaction has been developed for covalent redox proteins immobilization and biosensing for the first time. In this work, azido group modified HRP was covalently grafted on 4-ethylnylphenyl diazonium compound via CuAAC reaction and a novel electrochemical hydrogen peroxide biosensor was successfully fabricated. In this paper, a simple two-step approach for redox protein immobilization was introduced. Firstly, alkynyl-terminated film was formed on electrode surface by electrochemical reduction of 4-ethylnylphenyl (4-EP) diazonium compound. Then, horseradish peroxidase (HRP) modified with azido group was covalently immobilized onto the electrografted film via click reaction. Reflection absorption infrared (RAIR) spectroscopy and electrochemical methods were used to characterize the modification process. The results indicate that HRP retains its native structure and shows fast direct electron transfer. Moreover, the immobilized HRP shows excellent electrocatalytic reduction activity toward H 2O 2 with a linear range of 5.0 × 10 −6 to 9.3 × 10 −4 mol L −1.