A highly sensitive, direct and label-free technique for Hg2+ detection using Kelvin probe force microscopy

Chanho Park, Kuewhan Jang, Sangmyung Lee, Juneseok You, Soyoung Lee, Hyunsoo Ha, Kyungtak Yun, Junseop Kim, Howon Lee, Jinsung Park, Sungsoo Na

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)


For several decades, various nanomaterials have been used in a wide range of industrial fields, research areas, and commercial products. Among many nanomaterials, nano-sized mercury materials are one of the most widely used nanomaterials in real life. However, due to the high toxicity of Hg2+, it is imperative to develop an effective and practical detection method for Hg2+ to protect human health and environment. In this study, a highly sensitive, label-free method of detecting Hg2+ that requires only a single drop of solution was developed. The detection mechanism is based on the different surface potential arising from Hg2+ binding to mismatched thymine-thymine sequences, creating a very stable base pair. The surface potential is measured with Kelvin probe force microscopy (KPFM) to a molecular resolution. The developed method is capable of detecting 2 fmol of Hg2+, which is 500 times more sensitive than previously reported techniques. Moreover, our method can selectively detect Hg2+ and can also be applied to tap water and river water. This KPFM-based Hg2+ detection method can be used as an early detection technique for practical applications.

Original languageEnglish
Article number305501
Issue number30
Publication statusPublished - 2015 Jul 31

Bibliographical note

Publisher Copyright:
© 2015 IOP Publishing Ltd.


  • DNA
  • Kelvin probe force microscopy
  • atomic force microscopy
  • mercury ion
  • thymine

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Electrical and Electronic Engineering


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