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

Abstract

Fluorescently labeled DNA adsorbed on graphene oxide (GO) is a well-established sensing platform for detecting a diverse range of analytes. GO is a loosely defined material and its oxygen content may vary depending on the condition of preparation. Sometimes, a further reduction step is intentionally performed to decrease the oxygen content and the resulting material is called reduced GO (rGO). In this work, DNA adsorption and desorption from GO and rGO is systematically compared. Under the same salt concentration, DNA adsorbs slightly faster with a 2.6-fold higher capacity on rGO. At the same time, adsorbed DNA on rGO is more resistant to desorption induced by temperature, pH, urea, and organic solvents. Various lengths and sequences of DNA probes have been tested. When its complementary DNA (cDNA) is added as a model target analyte, the rGO sample has a higher signal-to-background and signalto-noise ratio, while the GO sample has a slightly higher absolute signal increase and faster signaling kinetics. Adsorbed DNAs on GO or rGO are still susceptible to non-specific displacement by other DNA and proteins. Overall, while rGO adsorb DNA more tightly, it allows efficient DNA sensing with an extremely low background signal.

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

“…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.…”

Electrochemical Detection of Zika Virus in Biological Samples: A Step for Diagnosis Point‐of‐care

“…The increase in the current is due to the presence of amino groups in polytyramine, providing positive charges to the formed film in the neutral medium of the anionic solution , allowing the electrostatic attraction with the redox pair. Still, the use of electrochemically reduced graphene oxide produces an increase in the surface area, allowing a greater formation of the polymer and, consequently, of more amino groups.…”

“…These organic functions are capable of interacting with the oligonucleotide by hydrogen bonds. Reduced graphene oxide also contains condensed aromatic rings, which can increase the binding affinity of the modified electrode with the oligonucleotide by π‐π stacking interactions .…”

Graphene Quantum Dot Oxidation Governs Noncovalent Biopolymer Adsorption

“…The preferential adsorption of ssDNA onto no-and low-ox-GQDs implies that ssDNA adsorbs more favorably onto graphene-like carbon domains rather than oxidized carbon domains. 47 This result points to the role of interfacial π-π electronic interactions between the GQD surface and aromatic ssDNA nitrogenous bases contributing more significantly to the overall physisorption process than hydrogen bonds between oxygen groups on the GQDs with the ssDNA. Likewise, the surface roughness created by oxygen groups on the med-and high-ox-GQDs could prevent π-π 10 interactions of nucleobases with the graphitic surface, thus inhibiting adsorption.…”

“…It is known that double-stranded DNA has a low adsorption affinity for GO surfaces, and this property has been previously used to study the adsorption affinity of ssDNA by cDNA-induced desorption. 47 The cDNA oligomer (AC)15 was added to either (GT)15-low-ox-GQD or (GT)15-noox-GQD solutions in five-fold excess relative to (GT)15. The resulting fluorescence profile of each GQD solution was measured 2 hours following addition of (AC)15 and compared with the initial fluorescence profile (Fig.…”