Thiolated Dendrimers as Multi-Point Binding Headgroups for DNA Immobilization on Gold

• Published in: Langmuir Vol. 27; no. 20; pp. 12434 - 12442
• Main Authors: Day, B. Scott, Fiegland, Larry R, Vint, Erik S, Shen, Wanqiu, Morris, John R, Norton, Michael L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 18.10.2011
• Subjects: Binding Sites; Chemistry; Dendrimers - chemistry; DNA - chemistry; Exact sciences and technology; General and physical chemistry; Gold - chemistry; Interfaces: Adsorption, Reactions, Films, Forces; Models, Biological; Molecular Structure; Polyamines - chemistry; Sulfhydryl Compounds - chemistry; Binding; Self assembly; Monolayer; Gold; Thiol; Branched polymer; Deprotection; Immobilization; Transition metal; High temperature; Oligomer; Buffer solution; Resistance; Substrate; Synthesis; Efficiency; DNA; Oligonucleotide; Dendritic structure
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la202444s

The synthesis of multithiolated DNA molecules that can be used to produce self-assembled monolayers of single-stranded DNA oligonucleotides on gold substrates is described. Generation 3 polyamidoamine (PAMAM) dendrimers were conjugated to DNA oligomers and functionalized with ∼30 protected thiol groups. The protected thiol groupsthioacetate groupsallowed the dendrimer–DNA constructs to be stored in a buffer solution for at least 2 months before deprotection without any observable decrease in their ability to assemble into functional layers. The monolayers formed using these multithiolated DNA probe strands demonstrate target capture efficiencies comparable to those of analogous monolayers assembled with DNA functionalized with single thiol groups. A functional advantage of using dendrimer headgroups is the resistance to probe strand loss in prolonged exposure to buffer solutions at a high temperature (95 °C).