title: Thiolated dendrimers as multi-point binding headgroups for DNA immobilization on gold.
abstract: 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).
authors.affiliation: Department of Chemistry, Marshall University, Huntington, West Virginia 25755, USA. day17@marshall.edu
authors.forename: B Scott
authors.initials: BS
authors.lastname: Day
authors.forename: Larry R
authors.initials: LR
authors.lastname: Fiegland
authors.forename: Erik S
authors.initials: ES
authors.lastname: Vint
authors.forename: Wanqiu
authors.initials: W
authors.lastname: Shen
authors.forename: John R
authors.initials: JR
authors.lastname: Morris
authors.forename: Michael L
authors.initials: ML
authors.lastname: Norton
mesh_terms: D001665:Binding Sites; D004247:DNA / Q000737:chemistry*; D050091:Dendrimers / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D008954:Models, Biological; D015394:Molecular Structure; D011073:Polyamines / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D050091:Dendrimers; C531249:Poly(amidoamine); D011073:Polyamines; D013438:Sulfhydryl Compounds; D006046:Gold; D004247:DNA