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Updated: May 12, 2026
High Resolution Physical Characterization of Single Metallic Nanoparticles
Published on: June 28, 2019
Highly selective and sensitive gold nanoparticle-based colorimetric assay for PO₄³⁻ in aqueous solution
Guangke He1, Liang Zhao, Kai Chen
1Department of Applied Chemistry, College of Science, Nanjing University of Technology, Jiangsu Key Laboratory of Industrial Water-Conservation and Emission Reduction, Nanjing 210009, People's Republic of China.
Abstract:
A rapid, simple and real-time colorimetric assay for detecting phosphate anions (PO₄(3-)) in aqueous solution was developed. The method was based on a novel functionalized gold nanoparticles (MPTP-Zn-AuNPs), which was synthesized by the ligand-exchange reaction of 4'-(4-mercaptophenyl)-2,2':6',2″-terpyridine zinc(II) complex (MPTP-Zn) with citrate-stabilized aqueous AuNPs. The strong coordination between MPTP-Zn-AuNPs and PO₄(3-) anion gave rise to a color change from wine-red to blue-gray that was discernible by the naked eye and an easily measurable alteration in the absorption spectrum of the particles in aqueous solution. And the new technique exhibited the high selectivity for PO₄(3-) over 11 other anions and could be used to determine PO₄(3-) with a detection limit of 11 ppm.
