Carboxylated single-wall carbon nanotubes decorated with SiO2 coated-Nd2O3 nanoparticles as an electrochemical sensor for L-DOPA detection

Abstract

L-DOPA (L-3,4-dihydroxyphenylalanine), the precursor of dopamine, is widely used in the treatment of Parkinson’s disease, thus determining and monitoring the concentration of L-DOPA is of utmost importance for both medical and scientific purposes. Although many analytical approaches, designed for drug detection and quantification, already exist, there is a constant need for modification of old and tailoring of new, faster, and selective methods. Redox active chemical species, such as L-DOPA, can be measured directly by electrochemical means, whereas electrochemical sensors combine sensitivity and selectivity within a small analytical device. This work demonstrates the development of such electrochemical sensor, based on carboxylated single-wall carbon nanotubes (SWCNT-COOH) decorated with SiO2 coated-Nd2O3 nanoparticles, and further application for the detection of L-DOPA. Developed SWCNT-COOH@Nd2O3-SiO2 sensor shows linear response in the range from 2 µmol L−1 to 52 µmol L−1 analyte concentration, and beside the low detection limit, it is characterized by a fast response time, as well as good life-time, reproducibility and repeatability.