A simple and sensitive sensor for silver ions based on unmodified gold nanoparticles by using dynamic light scattering techniques

A simple and sensitive assay for Ag+ was developed with unmodified gold nanoparticles (AuNPs) by using dynamic light scattering (DLS) techniques. Ag+ could induce the oligonucleotide (5`-ATC ACT ATA TCA TAT ACT CAT-3`) to change from a single-stranded structure to a double-stranded structure and desorb from the surface of AuNPs, which triggered the aggregation of AuNPs in the salt solution. The average hydrodynamic diameter of aggregated AuNPs could be detected by using DLS techniques. Under the optimum conditions, the average hydrodynamic diameter of AuNPs is proportional to the concentration of Ag+ within the range of 13.3 - 100.0 nM, with a detection limit of 3.2 nM. The method is easy to operate, and has low sample consumption, high sensitivity and selectivity.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author