Abstract
Clinical diagnostics and disease control are fields that strongly depend on technologies for rapid, sensitive, and selective detection of biological or chemical analytes. Nanoparticles have become an integral part in various biomedical detection devices and nanotherapeutics. An increasing focus is laid on gold nanoparticles as they express less cytotoxicity, high stability, and hold unique optical properties with the ability of signal transduction of biological recognition events with enhanced analytical performance. Strong electromagnetic field enhancements can be found in close proximity to the nanoparticle that can be exploited to enhance signals for e.g., metal-enhanced fluorescence or Raman spectroscopy. Even stronger field enhancements can be achieved with sharp-edged nanoparticles, which are synthesized with the help of facet blocking agents, such as cetyltrimethylammonium bromide/chloride (CTAB/CTAC). However, chemical modification of the nanoparticle surface is necessary to reduce the particle’s cytotoxicity, stabilize it against aggregation, and to bioconjugate it with biomolecules to increase its biocompatibility and/or specificity for analytical applications. Here, a reliable two-step protocol following a ligand exchange with bis (p-sulfonatophenyl) phenyl phosphine (BSPP) as the intermediate capping-agent is demonstrated, which results in the reliable biofunctionalization of CTAC-capped gold nanocubes with thiol-modified DNA. The functionalized nanocubes have been characterized regarding their electric potential, plasmonic properties, and stability against high concentrations of NaCl and MgCl2.
Highlights
Noble metal nanoparticles exhibit special physical and optical properties
To realize the binding of thiol-modified DNA oligonucleotides to gold nanocubes deriving from detergent-based synthesis, experiments testing various published functionalization methods aimed at particle biofunctionalization were conducted
The protocols were applied in their original form as published as well as with additional adjustments that are known to increase DNA-loading onto gold nanoparticles
Summary
Noble metal nanoparticles exhibit special physical and optical properties. This effect originates in the specific interaction of the metal nanoparticles upon irradiation with light. Collective oscillations of the conduction band electrons are induced that are known as ‘particle plasmons’ or localized surface plasmons (LSP) [1,2]. Due to their strong interaction with light in the visible spectrum and the strong field enhancements that can be found at edges and corners of such nanostructures [3], shape-anisotropic gold nanoparticles have become an integral part in various biomedical detection devices and nanotherapeutics. The high biocompatibility of gold nanoparticles especially facilitates their incorporation into biosensor designs that exhibit enhanced analytical performance [5]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
