Graphene quantum dots doped with sulfur and nitrogen as versatile electrochemical sensors for heavy metal ions Cd(II), Pb(II), and Hg(II)

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Authors

Saisree Sadasivakurup¹ , Sandhya Karunakaran Yesodha¹ , Arya Nair Jayadharan Salini¹

1. Indian Institute of Space Science and Technology

Conference / event

35th Kerala Science Congress, February 2023 (Kuttikanam, India)

Poster summary

A sulfur co-doped nitrogen-graphene quantum dot was synthesized from polyaniline using sulfuric acid as an acid catalyst and S-doping agent through a simple hydrothermal synthesis. The S,N-GQDs, for the first time, exhibited simultaneous sensing toward three of the top 10 toxic metal ions: Cd(II), Pb(II), and Hg(II) with highly sharp peaks and adequate peak-to-peak separation. The detection limit values were lowest hitherto for Cd(II), Pb(II), and Hg(II) on S,N-GQD with 1, 10, and 1 pM, respectively, for the simultaneous sensing of the metal ions. The significantly enhanced (~7-fold) sensitivity compared to that of N-GQD for Cd(II) and the simultaneous sensing capability of S,N-GQD is assigned to the co-doping with S, which enabled the sensing of Pb(II) and Hg(II) through the M(II)−S interactions and the enhanced electronic properties, respectively. Further, the actual environmental water sample studies accomplished ∼100% recovery in all the tested samples with a relative standard deviation of ≤0.5%.

Keywords

Graphene quantum dot, Electrochemical sensing, Lowest detection limit, Heteroatom doping, Heavy metal ions, Simultaneous sensing

Research areas

Chemistry

References

1. Saisree S, Arya Nair J. S, and Sandhya Karunakaran Yesodha, ‘Graphene Quantum Dots Doped with Sulfur and Nitrogen as Versatile Electrochemical Sensors for Heavy Metal Ions Cd(II), Pb(II), and Hg(II)’. ACS Applied Nano Materials, January 2023.
2. Aswathi Ramachandran, Arya Nair J S, and Sandhya Karunakaran Yesodha,'Polyaniline-Derived Nitrogen-Doped Graphene Quantum Dots for the Ultratrace Level Electrochemical Detection of Trinitrophenol and the Effective Differentiation of Nitroaromatics: Structure Matters'. ACS Sustainable Chemistry and Engineering, March 2019.

Funding

No data provided

Supplemental files

No data provided

Additional information

Competing interests

No competing interests were disclosed.

Data availability statement

The datasets generated during and / or analyzed during the current study are available from the corresponding author on reasonable request.

Creative Commons license

Copyright © 2023 Sadasivakurup et al. This is an open access work distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.