A highly sensitive, direct and label-free technique for Hg<sup>2+</sup> 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, Sung Soo Na

Research output: Contribution to journalArticlepeer-review

14 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 Hg<sup>2+</sup>, it is imperative to develop an effective and practical detection method for Hg<sup>2+</sup> to protect human health and environment. In this study, a highly sensitive, label-free method of detecting Hg<sup>2+</sup> that requires only a single drop of solution was developed. The detection mechanism is based on the different surface potential arising from Hg<sup>2+</sup> 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 Hg<sup>2+</sup>, which is 500 times more sensitive than previously reported techniques. Moreover, our method can selectively detect Hg<sup>2+</sup> and can also be applied to tap water and river water. This KPFM-based Hg<sup>2+</sup> detection method can be used as an early detection technique for practical applications.

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


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

ASJC Scopus subject areas

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

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