Preparation of Multiwalled Carbon Nanotubes: Electrochemically Treated Pencil Graphite Electrodes for Nanomolar Detection of L-Tryptophan in Complex Samples


Yildiz C., ESKİKÖY BAYRAKTEPE D., YAZAN Z.

CHEMISTRYSELECT, vol.7, no.40, 2022 (SCI-Expanded, Scopus)

  • Publication Type: Article / Article
  • Volume: 7 Issue: 40
  • Publication Date: 2022
  • Doi Number: 10.1002/slct.202201697
  • Journal Name: CHEMISTRYSELECT
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier
  • Keywords: Electrochemical pretreatment, L-Tryptophan, multi-walled carbon nanotubes, pencil graphite electrode, voltammetry, URIC-ACID, ASCORBIC-ACID, PASTE ELECTRODE, CAPILLARY-ELECTROPHORESIS, SENSITIVE DETERMINATION, VOLTAMMETRIC SENSOR, DOPAMINE, NANOPARTICLES, TYROSINE, LIQUID
  • Ankara University Affiliated: Yes

Abstract

The present work reports a sensitive and simple sensor based on an electrochemically treated pencil graphite electrode (pre-PGE) modified with multi-walled carbon nanotubes (MWCNTs) for electrochemical determination of L-tryptophan (L-Try) detection in the presence of uric acid. Electrochemical and physical characterizations of the MWCNTs/pre-PGE were investigated using cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) techniques. Under the optimized conditions, the linear working range was 0.030-200.0 mu M with a limit of detection of 9.0 nM using the differential pulse adsorptive stripping voltammetry (DPAdSV) method. The proposed sensor exhibited good sensitivity, repeatability, reproducibility, and stability. The MWCNTs/pre-PGE were successfully applied to L-Try determination in commercial poly-amino acid supplements with good recovery and accuracy.