Covalent functionalization of MoS2 nanosheets synthesized by liquid phase exfoliation to construct electrochemical sensors for Cd (II) detection

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Xiaorong Gan
  • Huimin Zhao
  • Kwok-Yin Wong
  • Yaobin Zhang
  • Xie Quan

Detail(s)

Original languageEnglish
Pages (from-to)38-48
Journal / PublicationTalanta
Volume182
Online published20 Feb 2018
Publication statusPublished - 15 May 2018
Externally publishedYes

Abstract

Surface functionalization is an effective strategy in the precise control of electronic surface states of two-dimensional materials for promoting their applications. In this study, based on the strong coordination interaction between the transition-metal centers and N atoms, the surface functionalization of few-layer MoS2 nanosheets was successfully prepared by liquid phase exfoliation method in N, N-dimethylformamide (DMF), 1-methyl-2-pyrrolidinone, and formamide. The cytotoxicity of surface-functionalized MoS2 nanosheets was for the first time evaluated by the methylthiazolyldiphenyl-tetrazoliumbromide assays. An electrochemical sensor was constructed based on glass carbon electrode (GCE) modified by MoS2 nanosheets obtained in DMF, which exhibits relatively higher sensitivity to Cd2+ detection and lower cytotoxicity against MCF-7 cells. The mechanisms of surface functionalization and selectively detecting Cd2+ were investigated by density functional theory calculations together with various spectroscopic measurements. It was found that surface-functionalized MoS2 nanosheets could be generated through Mo-N covalent bonds due to the orbital hybridization between the 5 s orbitals of Mo atoms and the 2p orbitals of N atoms of the solvent molecules. The high selectivity of the sensor is attributed to the coordination reaction between Cd2+ and O donor atoms of DMF adsorbed on MoS2 nanosheets. The robust anti-interference is ascribed to the strong binding energy of Cd2+ and O atoms of DMF. Under the optimum conditions, the electrochemical sensor exhibits highly sensitive and selective assaying of Cd2+ with a measured detection limit of 0.2 nM and a linear range from 2 nM to 20 μM.

Research Area(s)

  • Cd2+, Electrochemical sensor, Few-layer MoS2 nanosheets, Liquid, Phase exfoliation, Surface functionalization

Citation Format(s)

Covalent functionalization of MoS2 nanosheets synthesized by liquid phase exfoliation to construct electrochemical sensors for Cd (II) detection. / Gan, Xiaorong; Zhao, Huimin; Wong, Kwok-Yin; Lei, Dang Yuan; Zhang, Yaobin; Quan, Xie.

In: Talanta, Vol. 182, 15.05.2018, p. 38-48.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review