Highly Sensitive Electrochemical Sensing Platform for the Detection of L-dopa Based on Electropolymerizing Glutathione Disulfide and Multi-walled Carbon Nanotube-modified Electrodes

Chengcheng Yang,Jiao Ma,Shu Zhu,Jinyi Song,Peiyao Ran,Yingzi Fu

doi:10.17159/0379-4350/2018/v71a24

Abstract

Afacile sensing platformfor the detection of L-dopa has been developed by electropolymerizing glutathione disulfide (PGSSG) on the surface of glass carbon electrodes (GCE) which were modified by multi-walled carbon nanotubes (MWCNTs). The electrochemical behaviour of the proposed electrodes were investigated via cyclic voltammetry (CV) and differential pulse voltammetry DPV). The morphology of the PGSSG and PGSSG/MWCNTs were characterized by scanning electron microscopy (SEM). Under the optimized experimental conditions, the sensing platform showed the linear response to L-Dopa in a range from 1.0 × 10–6 to 1.2 × 10–3 M with a detection limit of 3.3 × 10–7M (S/N = 3). Moreover, with the merits of high sensitivity and selectivity, good stability and reproducibility, the sensor was successfully applied for the determination of L-dopa in a real sample.Keywords: L-dopa, glutathione disulfide, multi-walled carbon nanotubes, electropolymerization, electrochemical determination

Highlights

Parkinson’s disease is a common degenerative disease of the nervous system, which is caused by serious shortage of dopamine in the brain
The multi-walled carbon nanotubes (MWCNTs)/glass carbon electrodes (GCE) were immersed into 3 mL phosphate buffer solution (PBS) containing 5 mM GSSG to electrolytic deposition for 10 cycles of cyclic voltammetry (PGSSG/MWCNTs/GCEs)
The preparation process of PGSSG/MWCNTs/GCE is shown in Scheme 1

Summary

Introduction

Parkinson’s disease is a common degenerative disease of the nervous system, which is caused by serious shortage of dopamine in the brain. Different techniques including spectrophotometry,[7] high performance liquid chromatography,[8] flow injection analysis,[9] capillary zone electrophoresis and spectrofluorimetry have been utilized for the determination of L-dopa.[10,11] These detection techniques often require complex equipment and the inspection processes are often cumbersome. Compared with these methods, the electrochemical methods have better performance because of their fast response, simple operation and low consumption of time. With the high electroactive surface area and excellent electrical conductivity, the PGSSG and MWCNT modified sensing platform exhibited high sensitivity and wide linear range for the measurement of L-dopa, and achieved sensitive detection of L-dopa in actual samples

Materials and Reagents

Results and Discussion

Electrochemical Behaviour of the Modified Electrodes

Conclusion