Biosensing Dopamine and L-Epinephrine with Laccase (Trametes pubescens) Immobilized on a Gold Modified Electrode

Abstract

Engineering electrode surfaces through the electrodeposition of gold may provide a range of advantages in the context of biosensor development, such as greatly enhanced surface area, improved conductivity and versatile functionalization. In this work we report on the development of an electrochemical biosensor for the laccase-catalyzed assay of two catecholamines—dopamine and L-epinephrine. Variety of electrochemical techniques—cyclic voltammetry, differential pulse voltammetry, electrochemical impedance spectroscopy and constant potential amperometry have been used in its characterization. It has been demonstrated that the laccase electrode is capable of sensing dopamine using two distinct techniques—differential pulse voltammetry and constant potential amperometry, the latter being suitable for the assay of L-epinephrine as well. The biosensor response to both catecholamines, examined by constant potential chronoamperometry over the potential range from 0.2 to −0.1 V (vs. Ag|AgCl, sat KCl) showed the highest electrode sensitivity at 0 and −0.1 V. The dependencies of the current density on either catecholamine’s concentration was found to follow the Michaelis—Menten kinetics with apparent constants KMapp = 0.116 ± 0.015 mM for dopamine and KMapp = 0.245 ± 0.031 mM for L-epinephrine and linear dynamic ranges spanning up to 0.10 mM and 0.20 mM, respectively. Calculated limits of detection for both analytes were found to be within the sub-micromolar concentration range. The biosensor applicability to the assay of dopamine concentration in a pharmaceutical product was demonstrated (with recovery rates between 99% and 106%, n = 3).

Highly sensitive amperometric sensors based on laccase-mimetic nanozymes for the detection of dopamine

“…34–40 The sensor described here, nAuCu/nAuPt/GCE has a 60-fold higher sensitivity compared to Hemin-doped HKUST-1/rGO and Lac–GA–NH 2 C 2 H 4 S–AuNS/GC sensors. 34,36…”

Review—Catalytic Electrochemical Biosensors for Dopamine: Design, Performance, and Healthcare Applications

“…However, the large electrode size renders the electrode unusable for measurements in confined environments such as those in in vivo conditions or cell culture environments. 98 Moreover, properties of these materials and their electrochemical responses may vary based on electrode design. For example, a procedure that allows for sensitive and reproducible results on a GCE may yield poor results in terms of signal-to-noise ratios and reproducibility when applied on a CFME due to changes in electrode surface area, hydrophobicity, capacitive current, and inhomogeneous coating of the electrode surface with the active layers.…”

Surface-Activated Pencil Graphite Electrode for Dopamine Sensor Applications: A Critical Review

“…Electroanalytical methods are a great alternative choice, having advantages such as easy sample preparation and cost-effective and instant results. In the past two decades, the development of electrochemical voltammetric techniques and the fabrication of low-cost modified electrodes for sensitive and selective DA estimation in body fluids has gained attention; ascorbic acid (AA) and uric acid (UA) interference-free detection of DA has been an especially challenging task [ 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. Various chemically modified electrodes have been constructed based on organic redox mediators [ 28 ], polymers-modified electrodes [ 29 , 30 ], metal nanocomposites [ 31 , 32 , 33 ] and nanoparticle-modified electrodes [ 34 ].…”