title: Synergetic approach for simple and rapid conjugation of gold nanoparticles with oligonucleotides.
abstract: Attaching thiolated DNA on gold nanoparticles (AuNPs) has been extremely important in nanobiotechnology because DNA-AuNPs combine the programmability and molecular recognition properties of the biopolymers with the optical, thermal, and catalytic properties of the inorganic nanomaterials. However, current standard protocols to attach thiolated DNA on AuNPs involve time-consuming, tedious steps and do not perform well for large AuNPs, thereby greatly restricting applications of DNA-AuNPs. Here we demonstrate a rapid and facile strategy to attach thiolated DNA on AuNPs based on the excellent stabilization effect of mPEG-SH on AuNPs. AuNPs are first protected by mPEG-SH in the presence of Tween 20, which results in excellent stability of AuNPs in high ionic strength environments and extreme pHs. A high concentration of NaCl can be applied to the mixture of DNA and AuNP directly, allowing highly efficient DNA attachment to the AuNP surface by minimizing electrostatic repulsion. The entire DNA loading process can be completed in 1.5 h with only a few simple steps. DNA-loaded AuNPs are stable for more than 2 weeks at room temperature, and they can precisely hybridize with the complementary sequence, which was applied to prepare core-satellite nanostructures. Moreover, cytotoxicity assay confirmed that the DNA-AuNPs synthesized by this method exhibit lower cytotoxicity than those prepared by current standard methods. The proposed method provides a new way to stabilize AuNPs for rapid and facile loading thiolated DNA on AuNPs and will find wide applications in many areas requiring DNA-AuNPs, including diagnosis, therapy, and imaging.
authors.affiliation: The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Collaborative Innovation Center of Chemistry for Energy Materials, the Key Laboratory of Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, China.
authors.forename: Jiuxing
authors.initials: J
authors.lastname: Li
authors.forename: Binqing
authors.initials: B
authors.lastname: Zhu
authors.forename: Xiujie
authors.initials: X
authors.lastname: Yao
authors.forename: Yicong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhu
authors.forename: Song
authors.initials: S
authors.lastname: Tu
authors.forename: Shasha
authors.initials: S
authors.lastname: Jia
authors.forename: Rudi
authors.initials: R
authors.lastname: Liu
authors.forename: Huaizhi
authors.initials: H
authors.lastname: Kang
authors.forename: Chaoyong James
authors.initials: CJ
authors.lastname: Yang
mesh_terms: D004247:DNA / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D009841:Oligonucleotides / Q000737:chemistry*; D010316:Particle Size; D056951:Photoelectron Spectroscopy; D011092:Polyethylene Glycols / Q000737:chemistry; D011136:Polysorbates / Q000737:chemistry; D012015:Reference Standards; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D009841:Oligonucleotides; D011136:Polysorbates; D013438:Sulfhydryl Compounds; D013501:Surface-Active Agents; D011092:Polyethylene Glycols; D006046:Gold; C028210:monomethoxypolyethylene glycol; D004247:DNA
keywords: DNA conjugation; Gold nanoparticle; bioconjugation; self-assembly; surface modification; surfactants