Aggregation-based determination of mercury(II) using DNA-modified single gold nanoparticle, T-Hg(II)-T interaction, and single-particle ICP-MS

Mikrochim Acta. 2019 Dec 17;187(1):56. doi: 10.1007/s00604-019-4057-6.

Abstract

An ultrasensitive assay is described for the detection and determination of Hg2+(aq) in water samples based on single-particle inductively-coupled plasma/mass spectrometry (spICP-MS). In the presence of Hg2+(aq), AuNPs modified with a segment of single-stranded DNA aggregate due to the formation of the well-known thymine (T)-Hg2+-T complex. Single particle (sp) ICP-MS is used quantify the degree of aggregation by the overall decrease in number of detected AuNPs or NP aggregates. Compared with most other Hg2+ assays that use the same principle of aggregation-dispersion with DNA modified AuNPs, this method has a much lower detection limit of (0.031 ng L-1, 155 fM) and a wider (10,000-fold) linear range (up to 1 μg L-1). The method also showed good practical potential because of its minimal interference from the water sample matrix. Graphical abstractSchematic representation of Hg2+ determination by using modified AuNP probes measured by spICP-MS. AuNPs pulses detected in ICP-MS is relative to the aggregation status of AuNPs based on thymine-Hg2+-thymine interaction.

Keywords: Inductively coupled plasma mass spectrometry; Ionic mercury; Sub ng L−1 detection.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • DNA / chemistry*
  • Gold / chemistry*
  • Mass Spectrometry
  • Mercury / analysis*
  • Metal Nanoparticles / chemistry*
  • Particle Size
  • Surface Properties

Substances

  • Gold
  • DNA
  • Mercury