Simultaneous electrochemical determination of dopamine and epinephrine using gold nanocrystals capped with graphene quantum dots in a silica network

Victor Vinoth, Lakshmi Nochur Natarajan, Ramalinga Viswanathan Mangalaraja, Héctor Valdés, Sambandam Anandan

Research output: Contribution to journalArticlepeer-review

27 Scopus citations

Abstract

Gold nanocrystals (AuNCs) were synthesized by economical and green strategy in aqueous medium by using N[3(trimethoxysilyl)propyl]ethylenediamine (TMSPED) as both a reducing and stabilizing mediator to avoid the aggregation of gold nanocrystals. Then, the AuNCs were capped with graphene quantum dots (GQDs) using an ultrasonic method. The resulting nanocomposites of GQD-TMSPED-AuNCs were characterized by X-ray photoelectron, X-ray diffraction, Raman, UV-vis and FT-IR spectroscopies. The size and shape of the nanocomposites were confirmed by using transmission electron microscopy and atomic force microscopy. The GQD-TMSPED-AuNCs placed on a glassy carbon electrode enable simultaneous determination of dopamine (DA) and epinephrine (EP) with peak potentials at 0.21 and 0.30 V (vs. Ag/AgCl). The response is linear in the 5 nM – 2.1 μM (DA) and 10 nM – 4.0 μM (EP) concentration ranges, with detection limits of 5 and 10 nM, respectively. The sensor shows good selectivity toward DP and EP in the presence of other molecules, facilitating its rapid detection in practical applications. [Figure not available: see fulltext.].

Original languageEnglish
Article number681
JournalMicrochimica Acta
Volume186
Issue number10
DOIs
StatePublished - 1 Oct 2019
Externally publishedYes

Keywords

  • Catecholamines
  • Drug analysis
  • Electrochemical sensors
  • N-[3(trimethoxysilyl)propyl]ethylenediamine
  • Nanocomposites

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