Fabrication of the carbon paste electrode modified with Trametes versicolor laccase immobilized on carboxyl functionalized multi-walled carbon nanotubes and its application for measurement of dopamine

• Published in: International journal of biological macromolecules 2024-12, Vol.283 (Pt 4), p.137891, Article 137891
• Main Authors: Moradpour, Hediyeh, Forootanfar, Hamid, Ameri, Atefeh, Beitollahi, Hadi
• Format: Article
• Language: English
• Subjects: Biosensing Techniques - methods; Biosensor; Carbon - chemistry; Dopamine - analysis; Dopamine - chemistry; Electrodes; Enzymes, Immobilized - chemistry; Enzymes, Immobilized - metabolism; Hydrogen-Ion Concentration; Laccase - chemistry; Laccase - metabolism; Laccase immobilization; Limit of Detection; Modified electrode; Nanotubes, Carbon - chemistry; Polyporaceae - enzymology; Temperature; Trametes - enzymology
• ISSN: 0141-8130; 1879-0003; 1879-0003
• DOI: 10.1016/j.ijbiomac.2024.137891

Dopamine (DA) shows numerous roles in a wide range of physiological and pathological processes. In this study, an immobilized laccase-derived biosensor was developed for DA detection. The carboxyl functionalized multi-walled carbon nanotubes (MWCNTs-COOH) was applied for immobilization of laccase from Trametes versicolor (TvLac). According to Plackett-Burman statistical design, the optimum conditions showed at 5 mg/mL of MWCNTs-COOH, 25 mM phosphate buffer (pH 6.0), sonication time for 15 min, 2.5 U/mg of enzyme concentration, immobilization time for 4 h at 4 °C, and rotation at 100 rpm. At these conditions, the experimental and predicted specific activities were 14.19 ± 1.41 U/mg and 13.99 ± 1.54 U/mg, respectively. The activity of immobilized TvLac was >90 % at 60 °C and pH 7.0 as well as after 10 sets of uses. The carbon paste electrode (CPE) modified with the immobilized TvLac was then fabricated, characterized and applied as a biosensor (TvLac@MWCNTs-COOH/CPE) for determination of DA. The mean of diffusion coefficient for DA was considered to be 9.1 × 10−6 cm2/s. The TvLac@MWCNTs-COOH/CPE represented a linear dynamic range of 0.005–100.0 μM with detection limit of 1.0 nM. The TvLac@MWCNTs-COOH/CPE might be introduced as a suitable sensor for monitoring of DA in real specimens which merit further studies. [Display omitted]