Covalent and Noncovalent Functionalization of Graphene Oxide with DNA for Smart Sensing

Abstract

Interfacing nanomaterials with DNA has resulted in the development of numerous biosensors, optimized for different targets and applications. Of all nanomaterials, graphene oxide (GO) has emerged as a prime sensing platform due to its high specific surface area, good aqueous stability, varied functional groups and desirable surface, and electrical and optical properties. This review starts with an introduction of GO and describes its physical and chemical properties. Then, the general strategies of interfacing DNA and GO to develop sensors are discussed. The trends in GO/DNA biosensor development are organized into classes based on the mode of DNA interaction with GO (physisorbed vs chemisorbed). Due to the intermediate DNA adsorption strength on GO, most of the sensors developed utilize physisorption of DNA to GO. Even within the realm of physisorbed probes, there are multiple sensing methods: direct adsorption, inhibited adsorption, competitive adsorption with the use of blocking agents, and tethered adsorption containing a strongly adsorbing block of DNA. Covalently linked DNA probes are also used to increase the biosensor stability. Each of these sensors has its advantages and disadvantages and the designs are discussed with representative examples in detail.

Graphene oxide-graphene Van der Waals heterostructure transistor biosensor for SARS-CoV-2 protein detection

“…1 f–g. The V Dirac right shift indicates that the graphene is p-doped after GO stack on the graphene through π-π stacking [ 48 , 49 ]. The mobility of GO/Gr heterojunction FET is increased by about 1.5 times comparing to the Gr FET, which greatly improves the performance of the device due to the effective patch of the graphene detects and suppression of surface ions absorption [ 50 , 51 ].…”

The Structure–Properties–Cytotoxicity Interplay: A Crucial Pathway to Determining Graphene Oxide Biocompatibility

“…Graphene oxide is considered a promising material for applications in many industries due to its excellent water processability, amphiphilicity, covalent and non-covalent surface functionalization, and ability to quench fluorescence [6][7][8][9][10][11]. GO is highly chemically active due to the partial coverage of its elemental planes and edges with various functional groups, mainly hydroxyl and epoxy, ketone, ester, organosulfur, and lactol structures in the dry state.…”

Sequence-Independent DNA Adsorption on Few-Layered Oxygen-Functionalized Graphene Electrodes: An Electrochemical Study for Biosensing Application

“…Nevertheless, further investigation is necessary to rationalize the high sensitivity at very low target concentration and the downward concentration trend. We propose that, in future applications, the strong adsorption of the probe in the presence of Mg 2+ and intense surface hybridization signal would eliminate the steps involved in covalent immobilization of a probe (chemisorption) [14] or expensive modification of the probe with 1-pyrenebutanoic acid succinimidyl ester (PASE) linker for stronger π-π interactions with graphene surface [45]. In contrast to other electrochemical detection of TNRs [46,47], this label-free GO x platform does not rely on guanine oxidation for sensing-therefore, a noninvasive method-and shows higher sensitivity down to the attomolar level compared to a recently reported solution-gated graphene transistor having detection limit only up to femtomolar range.…”

“…To harness the properties of such interfaces for sensitive biosensing platforms, interactions of nucleic acids with graphene-based surfaces have been extensively studied in two regimes, i.e., physisorption and chemisorption [14]. The interfacing of DNA and graphene surfaces is often achieved by the simple mixing of DNA oligonucleotide solution with graphene solution (a liquid/liquid interface) to form DNA-graphene hybrids [15,16], and DNA self-assembly on graphene electrodes (a liquid/solid interface) [17].…”