Surface Passivation Improves the Synthesis of Highly Stable and Specific DNA-Functionalized Gold Nanoparticles with Variable DNA Density

DOI: 10.1021/acsami.5b01191
PMID: 25756758

Authors: Jashmini Deka (Elettra-Sincrotrone Trieste) , Rostislav Měch (Brno University of Technology) , Luca Ianeselli (Elettra-Sincrotrone Trieste) , Heinz Amenitsch (Graz University of Technology) , Fernando Cacho-nerin (Diamond Light Source; Graz University of Technology) , Pietro Parisse (INSTM − ST Uni) , Loredana Casalis (Elettra-Sincrotrone Trieste)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Acs Applied Materials & Interfaces , VOL 7 , PAGES 7033 - 7040

State: Published (Approved)
Published: April 2015

Abstract: We report a novel and multifaceted approach for the quick synthesis of highly stable single-stranded DNA (ssDNA) functionalized gold nanoparticles (AuNPs). The method is based on the combined effect of surface passivation by (1-mercaptoundec-11-yl)hexa(ethylene glycol) and low pH conditions, does not require any salt pretreatment or high excess of ssDNA, and can be generalized for oligonucleotides of any length or base sequence. The synthesized ssDNA-coated AuNPs conjugates are stable at salt concentrations as high as 3.0 M, and also functional and specific toward DNA–DNA hybridization, as shown from UV–vis spectrophotometry, scanning electron microscopy, gel electrophoresis, fluorescence, and small angle X-ray scattering based analyses. The method is highly flexible and shows an additional advantage of creating ssDNA-AuNP conjugates with a predefined number of ssDNA strands per particle. Its simplicity and tenability make it widely applicable to diverse biosensing applications involving ssDNA functionalized AuNPs.

Journal Keywords: DNA functionalization; gold nanoparticles; surface passivation; oligo ethylene glycol; salt-stability; specificity; variable DNA density

Subject Areas: Engineering, Chemistry


Technical Areas: