Electrochemical sensor for detecting dopamine using graphene quantum dots incorporated with multiwall carbon nanotubes

• Published in: Applied surface science 2020-04, Vol.508, p.145294, Article 145294
• Main Authors: Arumugasamy, Shiva Kumar, Govindaraju, Saravanan, Yun, Kyusik
• Format: Article
• Language: English
• Subjects: Dopamine; Electrochemical sensor; GQDs; MWCNTs; Nanocomposite
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2020.145294

•Nanocomposite of graphene quantum dots (GQDs, 1–5 nm) and multiwall carbon nanotubes (MWCNTs) had been synthesized using modest approach for electrochemical sensing of dopamine.•Typical size of GQDs were found to be 1–5 nm being measured using TEM and AFM techniques.•Differential pulse voltammetry (DPV) technique had been performed over a linear range of 0.25–250 μM and the LOD was determined to be to be 95 nM.•Real sample analysis had also been performed using serum samples. A ratiometric electrochemical biosensor was developed for dopamine detection based on the incorporation of graphene quantum dots (GQDs) with acid-functionalized multiwall carbon nanotubes (MWCNTs) on a glassy carbon electrode (GCE) surface. The GQDs@MWCNTs/GCE nanocomposite was characterized by XRD, SEM, TEM, AFM, XPS, and electrochemical techniques. The UV absorbance peak of GQDs was located at 235 nm, and the average size of the GQDs was 1–5 nm. The electrochemical responses indicated that the proposed sensor exhibited good electrocatalytic activity toward the oxidation of dopamine and spiked dopamine, over a dynamic linear range of 0.25–250 μM, with low detection limits of 95 nM and 110 nM (S/N = 3), respectively. In addition, the developed sensor interacted selectively with dopamine rather than other molecules was investigated using an amperometric technique. The developed sensor exhibited excellent reproducibility, selectivity, and sensitivity.