title: Disulfide-induced self-assembled targets: A novel strategy for the label free colorimetric detection of DNAs/RNAs via unmodified gold nanoparticles.
abstract: A modified non-cross-linking gold-nanoparticles (Au-NPs) aggregation strategy has been developed for the label free colorimetric detection of DNAs/RNAs based on self-assembling target species in the presence of thiolated probes. Two complementary thiol- modified probes, each of which specifically binds at one half of the target introduced SH groups at both ends of dsDNA. Continuous disulfide bond formation at 3' and 5' terminals of targets leads to the self-assembly of dsDNAs into the sulfur- rich and flexible products with different lengths. These products have a high affinity for the surface of Au-NPs and efficiently protect the surface from salt induced aggregation. To evaluate the assay efficacy, a small part of the citrus tristeza virus (CTV) genome was targeted, leading to a detection limit of about 5 × 10-9mol.L-1over a linear ranged from 20 × 10-9to 10 × 10-7mol.L-1. This approach also exhibits good reproducibility and recovery levels in the presence of plant total RNA or human plasma total circulating RNA extracts. Self-assembled targets can be then sensitively distinguished from non-assembled or mismatched targets after gel electrophoresis. The disulfide reaction method and integrating self-assembled DNAs/RNAs targets with bare AuNPs as a sensitive indicator provide us a powerful and simple visual detection tool for a wide range of applications.
authors.affiliation: Department of Life Science Engineering, Faculty of New Sciences &Technologies, University of Tehran, Tehran, Iran.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Shokri
authors.affiliation: Department of Life Science Engineering, Faculty of New Sciences &Technologies, University of Tehran, Tehran, Iran.
authors.forename: Morteza
authors.initials: M
authors.lastname: Hosseini
authors.affiliation: Lehrstuhl für Biotechnologie, RWTH Aachen University, 52056 Aachen, Germany.
authors.forename: Mehdi D
authors.initials: MD
authors.lastname: Davari
authors.affiliation: Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran, Iran.|Biosensor Research Center, Endocrinology &Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Ganjali
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Maikel P
authors.initials: MP
authors.lastname: Peppelenbosch
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus Medical Center, Rotterdam, The Netherlands.|Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Farhad
authors.initials: F
authors.lastname: Rezaee
mesh_terms: D017790:Closterovirus / Q000235:genetics; D003124:Colorimetry / Q000379:methods*; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D015342:DNA Probes / Q000138:chemical synthesis; D004220:Disulfides / Q000737:chemistry*; D006046:Gold; D053768:Metal Nanoparticles; D018625:Microscopy, Atomic Force; D012313:RNA / Q000032:analysis* / Q000737:chemistry; D015347:RNA Probes / Q000138:chemical synthesis
chemical_list: D015342:DNA Probes; D004220:Disulfides; D015347:RNA Probes; D012313:RNA; D006046:Gold; D004247:DNA