The time-dependent progression from gold nanosponges (AuNS) to discrete small gold nanoparticles (AuNPs) mediated by H2O2 in MES buffer is blocked by the addition of a thiol, glutathione. This represents an important improvement for the plasmonic ELISA, and also leads to a time-dependent approach for the synthesis of AuNS and AuNPs in water with precise control over nanostructure size.
