title: Cross-Linking versus Non-Cross-Linking Aggregation of Gold Nanoparticles Induced by DNA Hybridization: A Comparison of the Rapidity of Solution Color Change.
abstract: Gold nanoparticles densely modified with single-stranded DNA (ssDNA-AuNPs) form aggregates with cross-linker ssDNAs via duplex formation. Alternatively, the ssDNA-AuNPs are spontaneously aggregated at high ionic strength in a non-cross-linking manner when complementary ssDNAs are added to form fully matched duplexes. Both aggregation modes are accompanied by a red-to-purple color change, which has been exploited in various bioassays. The current study compares the rapidity of color change between the cross-linking and non-cross-linking aggregation modes under identical conditions. When a small number of cross-linker/complementary DNAs are provided, the cross-linking mode exhibited more rapid color change than the non-cross-linking mode. Conversely, with a large number of the DNAs, the non-cross-linking aggregation occurred more rapidly than the cross-linking counterpart. This finding allows one to select a more appropriate aggregation mode for application of ssDNA-AuNPs to colorimetric assays under given conditions.
authors: Bioengineering Laboratory, RIKEN , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors: Guoqing
authors: G
authors: Wang
authors: Bioengineering Laboratory, RIKEN , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors: Yoshitsugu
authors: Y
authors: Akiyama
authors: Bioengineering Laboratory, RIKEN , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors: Shota
authors: S
authors: Shiraishi
authors: Bioengineering Laboratory, RIKEN , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors: Naoki
authors: N
authors: Kanayama
authors: Bioengineering Laboratory, RIKEN , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors: Tohru
authors: T
authors: Takarada
authors: Bioengineering Laboratory, RIKEN , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors: Mizuo
authors: M
authors: Maeda
mesh_terms: D003116:Color; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D012996:Solutions
chemical_list: D012996:Solutions; D006046:Gold