Is a Stop Solution Necessary for Metal Nanoparticles Aggregation-based Colorimetric Assays?

Abstract

We report herein for the first time that a stop solution should be used to terminate the metal nanoparticles aggregation reactions especially salt-induced ones to increase the repeatability of the assays. It was found that hydrophobic surfactants have the ability to slow down the aggregation process of MNPs and can be applied as stop solution for aggregation based colorimetric assays. This trick provides accurate and well-repeatable signals since the aggregation of the nanoparticles is a dynamic process and capturing signal in a predetermined time is difficult.