Generic epitaxial graphene biosensors for ultrasensitive detection of cancer risk biomarker

Abstract

A generic electrochemical method of "bioreceptor" antibody attachment to phenyl amine functionalised graphitic surfaces is demonstrated. Micro-channels of chemically modified multi-layer epitaxial graphene (MLEG) have been used to provide a repeatable and reliable response to nano molar (nM) concentrations of the cancer risk (oxidative stress) biomarker 8hydroxydeoxyguanosine (8-OHdG). X-ray photoelectron spectroscopy, Raman spectroscopy are used to characterize the functionalised MLEG. Confocal fluorescence microscopy using fluorescent-labelled antibodies indicates that the anti-8-OHdG antibody selectively binds to the phenyl amine-functionalised MLEG's channel. Current-voltage measurements on functionalised channels showed repeatable current responses from antibody-biomarker binding events. This technique is scalable, reliable, and capable of providing a rapid, quantitative, label-free assessment of biomarkers at nano-Molar (less than 20 nM) concentrations in analyte solutions. The sensitivity of the sensor device was investigated using varying concentrations of 8-OHdG, with changes in the sensor's channel resistance observed upon exposure to 8-OHdG. Detection of 8-OHdG concentrations as low as 0.1ng/ml

Anti-epidermal growth factor receptor conjugated mesoporous zinc oxide nanofibers for breast cancer diagnostics

“…30 Tehrani et al fabricated microchannels of a chemically modified multi-layer epitaxial graphene based biosensor for the detection of a cancer biomarker (8-hydroxydeoxyguanosine) that is sensitive up to 0.35 nM. 35 However, the prepared biosensors can detect lower concentrations of ErbB2 compared to those of the reported biosensors (Table 1), 29,30,36,37 this may perhaps be because of the high surface area of mesoporous ZnOnFs for antibody conjugation. Table 1 shows the breast cancer sensing characteristics for the fabricated immunoelectrodes alongwith those reported in literature.…”

Prospective Life Cycle Assessment of Epitaxial Graphene Production at Different Manufacturing Scales and Maturity

“…) and as a biosensor, which could be used to indicate cancer and other diseases (Tehrani et al. ). Epitaxial graphene is suggested as suitable for these applications because of its high quality and because it can be grown directly on silicon carbide (SiC) semiconductor substrates without any need for transfer (Novoselov et al.…”

“…Similarly to CVD, epitaxial growth provides graphene in the form of a thin surface layer. Graphene produced by epitaxial growth has been suggested as a potential substitute for silicon as semiconductor material in microchips (Van Noorden 2006;Zhou et al 2007) and as a biosensor, which could be used to indicate cancer and other diseases (Tehrani et al 2014). Epitaxial graphene is suggested as suitable for these applications because of its high quality and because it can be grown directly on silicon carbide (SiC) semiconductor substrates without any need for transfer (Novoselov et al 2012;Sivudu and Mahajan 2012;Hertel et al 2012).…”

Magnetoresistance of Mn-decorated topological line defects in graphene

“…It has been observed in as-grown graphene [5] and can also be induced in a controlled fashion by electron irradiation [6,7]. In general, the intentional introduction of defects into graphene is a topic that currently receives enormous attention, because it can lead to a multitude of applications [8][9][10][11][12][13][14]. Moreover, the interactions between defects in graphene and metal atoms have been explored extensively in the literature [15][16][17][18][19].…”