Adsorption of DNA onto gold nanoparticles and graphene oxide: surface science and applications

Abstract

The interaction between DNA and inorganic surfaces has attracted intense research interest, as a detailed understanding of adsorption and desorption is required for DNA microarray optimization, biosensor development, and nanoparticle functionalization. One of the most commonly studied surfaces is gold due to its unique optical and electric properties. Through various surface science tools, it was found that thiolated DNA can interact with gold not only via the thiol group but also through the DNA bases. Most of the previous work has been performed with planar gold surfaces. However, knowledge gained from planar gold may not be directly applicable to gold nanoparticles (AuNPs) for several reasons. First, DNA adsorption affinity is a function of AuNP size. Second, DNA may interact with AuNPs differently due to the high curvature. Finally, the colloidal stability of AuNPs confines salt concentration, whereas there is no such limit for planar gold. In addition to gold, graphene oxide (GO) has emerged as a new material for interfacing with DNA. GO and AuNPs share many similar properties for DNA adsorption; both have negatively charged surfaces but can still strongly adsorb DNA, and both are excellent fluorescence quenchers. Similar analytical and biomedical applications have been demonstrated with these two surfaces. The nature of the attractive force however, is different for each of these. DNA adsorption on AuNPs occurs via specific chemical interactions but adsorption on GO occurs via aromatic stacking and hydrophobic interactions. Herein, we summarize the recent developments in studying non-thiolated DNA adsorption and desorption as a function of salt, pH, temperature and DNA secondary structures. Potential future directions and applications are also discussed.Aside from molecular recognition, DNA-surface interaction has attracted more and more attention for the following two reasons. First, many technologies require DNA immobilization

Comprehensive Screen of Metal Oxide Nanoparticles for DNA Adsorption, Fluorescence Quenching, and Anion Discrimination

“…For metallic nanoparticles (e.g., AuNPs) and carbon-based nanomaterials (e.g., graphene oxide and carbon nanotubes), DNA adsorption is achieved mainly via base interaction. [8][9][39][40][41] For example, adding phosphate has little effect on DNA adsorbed by these materials. Many MONPs (e.g., TiO2, CeO2, ITO) adsorb DNA mainly via the phosphate 10 backbone.…”

“…[1][2][3][4][5][6] While DNA has been interfaced with metal and carbon-based nanomaterials, [6][7][8][9] limited work was carried out on metal oxide nanoparticles (MONPs). [10][11][12][13][14][15][16][17][18][19][20] MONPs represent a very important class of material due to their unique electronic, optical, magnetic and catalytic properties.…”

Rationally Designed Nucleobase and Nucleotide Coordinated Nanoparticles for Selective DNA Adsorption and Detection

“…[18][19][20][21][22] We reason that this problem might be overcome by introducing more specific intermolecular forces based on the properties of the target molecules. For this purpose, DNA is an ideal model target to obtain fundamental insights since arbitrary sequences and modifications are readily accessible through chemical DNA synthesis.…”

“…For example, citrate-capped gold nanoparticles (AuNPs) strongly bind to DNA bases. [18][19][20][21][22] Negatively charged graphene oxide (GO) adsorbs DNA via hydrophobic interactions, hydrogen bonding and π-π stacking. [23][24][25] In both cases, ss-DNA adsorbs much faster than ds-DNA.…”

“…It needs to be noted that poly-T DNA is usually a weak binder for most 10 materials (e.g with AuNPs or graphene oxide). 22 Therefore, it is quite remarkable to have a material that binds to poly-T DNA more favorably. To further understand the adsorption mechanism, the same experiment was repeated in the absence of salt ( Figure 3B), where little adsorption was observed for all the sequences.…”