Hybrids of Nucleic Acids and Carbon Nanotubes for Nanobiotechnology

Abstract

Recent progress in the combination of nucleic acids and carbon nanotubes (CNTs) has been briefly reviewed here. Since discovering the hybridization phenomenon of DNA molecules and CNTs in 2003, a large amount of fundamental and applied research has been carried out. Among thousands of papers published since 2003, approximately 240 papers focused on biological applications were selected and categorized based on the types of nucleic acids used, but not the types of CNTs. This survey revealed that the hybridization phenomenon is strongly affected by various factors, such as DNA sequences, and for this reason, fundamental studies on the hybridization phenomenon are important. Additionally, many research groups have proposed numerous practical applications, such as nanobiosensors. The goal of this review is to provide perspective on biological applications using hybrids of nucleic acids and CNTs.

Using a fluorescence quenching method to detect DNA adsorption onto single-walled carbon nanotube surfaces

“…A similar average value (2.0 ± 0.79 nm) was obtained when a mixture of T30 and SWNTs were sonicated under the standard conditions for SWNT solubilization that was employed by many other research groups (DNA: SWNTs = 1:1 in weight ratio; 90 min sonication under P60 condition). [5, 15] The data suggest that DNA-SWNTs had high monodispersity under the P20 and B conditions. On the other hand, there was no significant difference in lengths of DNA-SWNTs for all of the conditions tested.…”

“…We first took advantage of the unique fluorescence quenching effect of SWNTs on the adsorbed fluorescently labelled DNA, which provided an effective way to quantify the amount of DNA molecules adsorbed onto the SWNT surfaces. Secondly, as DNA adsorption onto SWNT surfaces causes an increase in SWNT diameter [5, 15, 30], we utilized AFM to measure the dimensions of individual DNA-SWNT hybrids based on their cross-section values in the images. This approach allowed us to directly assess the effects of sonication on the DNA-SWNT hybridization process.…”

“…[1–5] This solubilization technique allows for the separation of CNTs based on their chiralities. [6, 7] Furthermore, DNA-CNTs hybrids are attractive candidates for nanobiodevices that can be extensively employed in drug delivery and DNA sensing studies.…”

“…The majority of research investigations involving DNA-CNT hybridization used extensive sonication periods to prepare the hybrids. [5, 15] However, sonication can also cause damage to DNA molecules and CNTs. In order to evaluate DNA-single-walled carbon nanotube (SWNT) hybrids, several research groups have studied sonication effects during preparation.…”

Probe Microscopic Studies of DNA Molecules on Carbon Nanotubes

“…The mono-dispersed CNTs reveal superior electrical and optical properties. By using the mono-dispersed DNA-CNT hybrids in aqueous solutions, their use in various biological applications, such as nanobiosensors and drug delivery systems, has become possible [18,19,20,21,22,23,24,25,26]. In addition to experimental research, theoretical structural models of DNA-CNT hybrids have been proposed by several researchers [27,28,29,30,31,32].…”