Molybdenum Disulfide For Ultra-Low Detection Of Free Radicals: Electrochemical Response And Molecular Modeling

Keywords

Defect engineering; DFT calculations Supplementary material for this article is available online; Electrochemical detection; Glassy carbon; MoS 2

Abstract

Two-dimensional (2D) molybdenum disulfide (MoS2) offers attractive properties due to its band gap modulation and has led to significant research-oriented applications (i.e. DNA and protein detection, cell imaging (fluorescent label) etc.). In biology, detection of free radicals (i.e. reactive oxygen species and reactive nitrogen (NO∗) species are very important for early discovery and treatment of diseases. Herein, for the first time, we demonstrate the ultra-low (pico-molar) detection of pharmaceutically relevant free radicals using MoS2 for electrochemical sensing. We present picoto nano- molar level sensitivity in smaller MoS2 with S-deficiency as revealed by x-ray photoelectron spectroscopy. Furthermore, the detection mechanism and size-dependent sensitivity have been investigated by density functional theory (DFT) showing the change in electronic density of states of Mo atoms at edges which lead to the preferred adsorption of H2O2 on Mo edges. The DFT analysis signifies the role of size and S-deficiency in the higher catalytic activity of smaller MoS2 particles and, thus, ultra-low detection.

Publication Date

6-1-2017

Publication Title

2D Materials

Volume

4

Issue

2

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1088/2053-1583/aa636b

Socpus ID

85021360135 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85021360135

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