Detection of pH and Enzyme-Free H2O2 Sensing Mechanism by Using GdOx Membrane in Electrolyte-Insulator-Semiconductor Structure

Pankaj Kumar, Siddheswar Maikap, Jian Tai Qiu, Surajit Jana, Anisha Roy, Kanishk Singh, Hsin Ming Cheng, Mu Tung Chang, Rajat Mahapatra, Hsien Chin Chiu, Jer Ren Yang

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

A 15-nm-thick GdOx membrane in an electrolyte-insulator-semiconductor (EIS) structure shows a higher pH sensitivity of 54.2 mV/pH and enzyme-free hydrogen peroxide (H2O2) detection than those of the bare SiO2 and 3-nm-thick GdOx membranes for the first time. Polycrystalline grain and higher Gd content of the thicker GdOx films are confirmed by transmission electron microscopy (TEM) and X-ray photo-electron spectroscopy (XPS), respectively. In a thicker GdOx membrane, polycrystalline grain has lower energy gap and Gd2+ oxidation states lead to change Gd3+ states in the presence of H2O2, which are confirmed by electron energy loss spectroscopy (EELS). The oxidation/reduction (redox) properties of thicker GdOx membrane with higher Gd content are responsible for detecting H2O2 whereas both bare SiO2 and thinner GdOx membranes do not show sensing. A low detection limit of 1 μM is obtained due to strong catalytic activity of Gd. The reference voltage shift increases with increase of the H2O2 concentration from 1 to 200 μM owing to more generation of Gd3+ ions, and the H2O2 sensing mechanism has been explained as well.

Original languageEnglish
Article number434
JournalNanoscale Research Letters
Volume11
Issue number1
DOIs
Publication statusPublished - Dec 1 2016
Externally publishedYes

Keywords

  • Catalytic
  • EIS structure
  • Enzyme-free HO
  • GdO
  • pH detection
  • Sensing mechanism

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

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  • Cite this

    Kumar, P., Maikap, S., Qiu, J. T., Jana, S., Roy, A., Singh, K., Cheng, H. M., Chang, M. T., Mahapatra, R., Chiu, H. C., & Yang, J. R. (2016). Detection of pH and Enzyme-Free H2O2 Sensing Mechanism by Using GdOx Membrane in Electrolyte-Insulator-Semiconductor Structure. Nanoscale Research Letters, 11(1), [434]. https://doi.org/10.1186/s11671-016-1657-5