Graphene nanosheet-sandwiched platinum nanoparticles deposited on a graphite pencil electrode as an ultrasensitive sensor for dopamine

Nadeem Baig, Abdel Nasser Kawde*, Abdelaziz Elgamouz*, Mohamed Morsy, Ahmed Mohsen Abdelfattah, Rizafizah Othaman

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


An ultra-sensitive sensor of dopamine is introduced. The sensor is constructed by encapsulating platinum nanoparticles (PtNPs) between reduced graphene oxide (GR) nanosheets. The sandwiched PtNPs between GR layers acted as a spacer to prevent aggregation and provided a fine connection between the GR nanosheets to provide fast charge transfer. This specific orientation of the GR nanosheets and PtNPs on the graphite pencil electrode (GPE) substantially improved the electrocatalytic activity of the sensor. The synthesized graphene oxide and the fabricated sensor were comprehensively characterized by Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, field emission-scanning electron microscopy (FE-SEM), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and square wave voltammetry (SWV). The value of the charge transfer coefficient (α), apparent heterogeneous electron transfer rate constant (ks), and electroactive surface area for dopamine were found to be about 0.57, 8.99 s-1, and 0.81 cm2, respectively. The developed sensor is highly sensitive towards dopamine, and the detection limit is 9.0 nM. The sensor response is linear for dopamine concentration from 0.06 to 20 μM (R2 = 0.9991). The behavior of the sensor for dopamine in the presence of a high concentration of l(+) Ascorbic acid and other potential interferents was satisfactory. High recovery percentage between 90% and 105% in the human urine sample, good reproducibility, and facile fabrication of the electrode make it a good candidate for dopamine sensing.

Original languageEnglish
Pages (from-to)2057-2067
Number of pages11
JournalRSC Advances
Issue number4
StatePublished - 12 Jan 2022

Bibliographical note

Funding Information:
The authors would like to acknowledge the support from the Pure and Applied Chemistry Research Group, the Research

Publisher Copyright:
© The Royal Society of Chemistry.

ASJC Scopus subject areas

  • Chemistry (all)
  • Chemical Engineering (all)


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