Mechanism of DNA Adsorption and Desorption on Graphene Oxide

Abstract

Graphene oxide (GO) adsorbing a fluorophore-labeled single-stranded (ss) DNA serves as a sensor system because subsequent desorption of the adsorbed probe DNA from GO in the presence of complementary target DNA enhances the fluorescence. In this study, we investigated the interaction of single- and double-stranded (ds) DNAs with GO by using a fluorescently labeled DNA probe. Although GO is known to preferentially interact with ssDNA, we found that dsDNA can also be adsorbed on GO, albeit with lower affinity. Furthermore, the status of ssDNA or dsDNA previously adsorbed on the GO surface was investigated by adding complementary or noncomplementary DNA (cDNA or non-cDNA) to the adsorption complex. We observed that hybridization occurred between the cDNA and the probe DNA on the GO surface. On the basis of the kinetics driven by the incoming additional DNA, we propose a mechanism for the desorption of the preadsorbed probe DNA from the GO surface: the desorption of the GO-adsorbed DNA was facilitated following its hybridization with cDNA on the GO surface; when the GO surface was almost saturated with the adsorbed DNA, nonspecific desorption dominated the process through a simple displacement of the GO-adsorbed DNA molecules by the incoming DNA molecules because of the law of mass action. Our results can be applied to design appropriate DNA probes and to choose proper GO concentrations for experimental setups to improve specific signaling in many biosensor systems based on the GO platform.

Comparison of MoS2, WS2, and Graphene Oxide for DNA Adsorption and Sensing

“…For cytosine, the H of the CH3 group and the O atom are relatively closer to the substrates. In another theoretical study, the vdW force was also deemed critical and order of interaction was determined to be G > A/C > T. 34 The fact that guanine adsorbs very tightly is also consistent with our observation in this study 13 (vide infra). MoS2 and WS2 sheets stack to form bulk materials via vdW force.…”

“…7 To disperse in water and interface with biopolymers, graphene oxide (GO) is often used. [8][9][10] The interaction between GO and DNA has been extensively studied, [11][12][13][14][15] which has inspired the exploration of various other 2D materials.…”

Comparison of Graphene Oxide and Reduced Graphene Oxide for DNA Adsorption and Sensing

“…25 Initially the DNA release was very fast, followed by a slower phase. It is likely that some weakly adsorbed DNA are more efficiently desorbed followed by the more strongly adsorbed DNA.…”

“…21 Fundamental studies on the interaction between DNA and GO were also carried out. 11,[22][23][24][25][26][27][28][29][30][31][32] GO is a loosely defined material, and the oxygen content can vary quite a lot depending on the preparation condition. The adsorption affinity of DNA is likely to depend on the oxygen content.…”

Integrating graphene oxide, functional DNA and nucleic-acid-manipulating strategies for amplified biosensing

“…A recent study further indicates that the mechanism involves DNA-probe displacement from the GO surface followed by DNA hybridization in solution [70]. However, in another study, it is demonstrated that hybridization occurs between the target DNA and the DNA probe on the GO surface followed by the desorption of duplex DNA [71]. Further work is needed to determine the correct mechanism of these interactions.…”