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

• Published in: Mikrochimica acta (1966) 2020-01, Vol.187 (1), p.56-56, Article 56
• Main Authors: Xing, Yuqian, Han, Juan, Wu, Xu, Pierce, David T., Zhao, Julia Xiaojun
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Microengineering; Nanochemistry; Nanotechnology; Original Paper
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-019-4057-6

An ultrasensitive assay is described for the detection and determination of Hg 2+ (aq) in water samples based on single-particle inductively-coupled plasma/mass spectrometry (spICP-MS). In the presence of Hg 2+ (aq), AuNPs modified with a segment of single-stranded DNA aggregate due to the formation of the well-known thymine (T)-Hg 2+ -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 Hg 2+ 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 abstract Schematic representation of Hg 2+ 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-Hg 2+ -thymine interaction.