Adsorption Of DNA Bases Research Articles

Adsorption of DNA Bases on Two‐Dimensional Boron Sheets

AbstractUtilizing two‐dimensional (2D) sheets for DNA fingerprinting applications is an active field of research, with extensive research being carried out on graphene, h‐BN and transition metal dichalcogenides. In this theoretical study we propose the newly discovered 2D boron sheets (α, α1 and β1 sheets) as a promising adsorbate material for DNA fingerprinting applications. The relatively high binding energies of the DNA bases Adenine (A), thymine (T), guanine (G) and cytosine (C) and the DNA base pairs A:T and G:C on the sheets suggest stabilization of the DNA constructs on these sheets. The stabilization energies were found to be higher in comparison with graphene sheets. The stabilization of the adsorbed nucleobases were found to be mediated by Van‐der Waals interaction, with no direct chemical bond being formed between the DNA bases and the sheets, similar to the scenario in graphene and h‐BN sheets. Physisorption of the DNA bases was also reflected in the relatively small changes in the work function after adsorption.

Theoretical investigation on the adsorption of DNA bases on B/N-doped SWCNT surface by the first principle

A comparative study was conducted to investigate the adsorption properties and energy of the pure and B/N-doped single-walled carbon nanotubes (SWCNTs) for surface adsorbed DNA bases adenine(A), thymine(T), cytosine(C) and guanine(G), and the electronic structure of stable adsorption model by using density functional theory calculations with LDA (PWC) method. It shows that B-doping does not cause SWCNTs’ structural distortion but can affect their electronic structures, and the interaction between carbon nanotubes and DNA bases enhanced with, turning the DNA bases adsorption on the surface of SWCNTs to chemical adsorption. N-doping has no obvious effects on the electronic structure of SWCNTs and the DNA bases, which can just be modified by physical adsorption on N-doped carbon nanotubes surface. The study predicts that the a few-electron elements such as B-doping have more advantages in DNA bases adsorption on the surface of the SWCNTs compared with the multi-electron central elements like N-doping.

Detection of DNA Bases Using Fe Atoms and Graphene**Supported by the National Natural Science Foundation of China under Grant Nos 51301119 and 11204201, and the Natural Science Foundation for Young Scientists of Shanxi Province under Grant No 2013021010-1.

The adsorption of DNA bases on a magnetic probe composed of Fe atoms and graphene is studied by using first-principles calculations. The stability of geometry, the electronic structure and magnetic property are investigated. The results indicate that four DNA bases, i.e., adenine, thymine, cytosine and guanine, can all be adsorbed on the probe solidly. However, the magnetic moments of the composite structure can be observed only when adenine adsorbs on the probe. In the cases of the adsorption of the other three bases, the magnetic moments of the composite structure are zero. Based on the significant change of magnetic moment of the composite structure, adenine can be distinguished conveniently from thymine, cytosine and guanine. This work may provide a new way to detect DNA bases.

Theoretical Investigation on the Adsorption of DNA Bases on B-doped SWCNT Surface

Theoretical Investigation on the Adsorption of DNA Bases on B-doped SWCNT Surface

Insight into the interaction between DNA bases and defective graphenes: Covalent or non-covalent

Although some metal clusters and molecules were found to more significantly bind to defective graphenes than to pristine graphenes, exhibiting chemisorptions on defective graphenes, the present investigation shows that the adsorption of DNA bases on mono- and di-vacant defective graphenes does not show much difference from that on pristine graphene, and is still dominantly driven by noncovalent interactions. In the present study the adsorptions of the nucleobases, adenine (A), cytosine (C), guanine, (G), and thymine (T) on pristine and defective graphenes, are fully optimized using a hybrid-meta GGA density functional theory (DFT), M06-2X/6-31G*, and the adsorption energies are then refined with both M06-2X and B97-D/6-311++G**. Graphene is modeled as nano-clusters of C72H24, C71H24, and C70H24 for pristine, mono- and di-vacant defective graphenes, respectively, supplemented by a few larger ones. The result shows that guanine has the maximum adsorption energy in all of the three adsorption systems; and the sequence of the adsorption strength is G>A>T>C on the pristine and di-vacant graphene and G>T>A>C on the mono-vacant graphene. In addition, the binding energies of the DNA bases with the pristine graphene are less than the corresponding ones with di-vacant defective graphene; however, they are greater than those of mono-vacant graphene with guanine and adenine, while it is dramatic that the binding energies of mono-vacant graphene with thymine and cytosine appear larger than those of pristine graphene.

Adsorption of DNA Bases onto a Semiconductor Surface: Evidence for Surface-Mediated Promotion and Detection of Complementary Base Pair Formation

The adsorption of DNA basesadenine (A), thymine (T), guanine (G), and cytosine (C)and base pairs onto single-crystal n-CdSe substrates has been studied in several solvents, using the band gap photoluminescence (PL) of the semiconductor as a probe. In methanol solution, all four bases cause similar, reversible PL quenching, consistent with their acting as Lewis acids toward the surface. The PL changes can be well fit by a dead-layer model, indicating that adsorption increases the depletion width of the semiconductor by ∼200−300 A. In DMSO solution, there is no PL response to individual bases. However, the complementary A−T and G−C base pairs yield a PL response, providing evidence that the surface can promote base pair formation. The A−T and C−G responses in DMSO correspond to depletion width increases of ∼100 and 200 A and persist to ∼45 and 75 °C, respectively. Competition experiments reveal a preference for C−G binding at elevated temperatures. In chloroform solution, the PL response of C−G base pairs c...