DNA Strand Elongation Induced by Small Gold Nanoparticles at High Ethanol Content

Abstract

Small N-(2-mercaptopropionyl)glycine gold nanoparticles (AuNPs) of 1.6 nm core size were synthesized. The mode of binding and the effect of ethanol on DNA conformational changes induced by AuNPs nanoparticles were studied in detail by means of fluorescence and circular dichroism (CD) spectroscopy, zeta potential, dynamic light scattering (DLS), viscometric, and atomic force microscopy (AFM) methods. The measurements were done at different molar ratios R = C AuNPs /C DNA and at different ethanol content. Both spectroscopic and structural techniques revealed that the binding of AuNPs with DNA grooves largely prevailed up to 30% EtOH (v/v). For higher ethanol levels (from 40% to 65% EtOH (v/v)), all methods concurred by showing that AuNPs were able to induce DNA strand elongation, which preceded formation of the AuNPs/DNA groove complex. Moreover, under suitable R values and ethanol content, the CD spectra, DLS, and AFM experiments revealed that AuNPs nanoparticles induced the formation of a rather compact AuNPs/DNA complex. The results suggested that this form is a coiled DNA structure stabilized by AuNPs interconnections.

Covalent and Non‐Covalent DNA–Gold‐Nanoparticle Interactions: New Avenues of Research

“…Moreover, under suitable R values (R=C AuNPs /C DNA ) and ethanol contents, the CD spectra, dynamic light scattering and atomic force microscopy experiments revealed that AuNPs induced the formation of a rather compact AuNPs/DNA complex. The results suggested that this form is a coiled DNA structure stabilized by AuNPs interconnections . For small, citrate‐capped gold NPs (5 nm), the denaturation of the helix occurs to form the previously mentioned complex ssDNA‐AuNP (Figure and ) …”

“…The results suggestedt hat this form is ac oiled DNA structure stabilized by AuNPs interconnections. [95] For small, citrate-capped gold NPs (5 nm), the denaturation of the helix occurs to form the previously mentioned complex ssDNA-AuNP (Figure 10 and1 4). [44] Figure 14 shows the evolution of the absorbance intensity at 260 nm with varying temperatures and at differentD NA/AuNP ratios, showingadecay of absorbance intensity with increasing NP concentrations.…”

DNA conformational changes induced by cationic gemini surfactants: the key to switching DNA compact structures into elongated forms

“…The collapse process by which extended polynucleotide chains modify their structures into compact particles is called condensation, which is a common process for native genomes. 5 The controlled DNA condensation has been demonstrated to be possible with a variety of reagents such as enzymes, 6 multivalent ions, 7,8 alcohols, 9,10 polyamines, 11 metal complexes, 12 nanoparticles, 13 and cationic surfactants. [14][15][16][17][18] In this regard, the gemini surfactants have received a lot of attention recently due to its unique physicochemical properties, low cytotoxicity and potential bactericidal properties.…”

Encased Gold Nanoparticle Synthesis as a Probe for Oleuropein Self-Assembled Structure Formation

“…In this sense, the magnitude of the measured zeta potential is an indication of the repulsive force that is present and can be used to predict the long-term stability of the nanoparticle. Naturally, it also allows us to obtain information about the proximity of ligands that could neutralize the surface of charged nanoparticles [ 32 , 33 ].…”