Electronic Biosensing with Functionalized rGO FETs

Abstract

In the following we give a short summary of examples for biosensor concepts in areas in which reduced graphene oxide-based electronic devices can be developed into new classes of biosensors, which are highly sensitive, label-free, disposable and cheap, with electronic signals that are easy to analyze and interpret, suitable for multiplexed operation and for remote control, compatible with NFC technology, etc., and in many cases a clear and promising alternative to optical sensors. The presented areas concern sensing challenges in medical diagnostics with an example for detecting general antibody-antigen interactions, for the monitoring of toxins and pathogens in food and feed stuff, exemplified by the detection of aflatoxins, and the area of smell sensors, which are certainly the most exciting development as there are very few existing examples in which the typically small and hydrophobic odorant molecules can be detected by other means. The example given here concerns the recording of a honey flavor (and a cancer marker for neuroblastoma), homovanillic acid, by the odorant binding protein OBP 14 from the honey bee, immobilized on the reduced graphene oxide gate of an FET sensor.

Sensing at the Surface of Graphene Field‐Effect Transistors

“…[78] Attomolar level detections have also been reported occasionally [205] but such significantly improved sensitivities were not always consistent with the more generally observed nM-pM detection limit, [66,67] suggesting that more dedicated efforts are still needed to improve the reliability and the reproducibility of the sensing response. [206] This brings us back to some of the fundamental issues associated with graphene-based BioFETs (and BioFETs in general) as eventually, after carefully designing and controlling every steps of a GFET, we will be looking at the Debye screening effects as an obstacle to achieve ultimate detection of a relatively large biomolecule in physiological conditions as previously discussed in Section 2.5 and will be further reviewed in the next Section 5.2. Alternatively, the detection of biomolecules can also be achieved by monitoring pH changes during adsorption, thus circumventing the Debye screening effects as proton is negligibly small.…”

InP Nanowire Biosensor with Tailored Biofunctionalization: Ultrasensitive and Highly Selective Disease Biomarker Detection

“…When compared to similar devices in literature, the obtained detection limits of our InP nanowire biosensor development (LOD: protein 5.7 fM/DNA 1.4 fM) surpasses the detection sensitivity over several magnitudes of previous protein and DNA biosensor key studies using Graphene, 46,47 reduced Graphene oxide 48,49 and 2D transition metal chalcogenides (MoSe2) 50,51 in the FET configuration (see biosensor detection limit comparison in Supporting Information Table S2). When compared to InAs nanowire devices with a protein detection limit of 10 pM (Avidin), 8 our InP nanowire sensor shows far superior sensing performance.…”

“…Our results show specific detection limits to T. cruzi recombinant protein concentrations down to ~30 fM, with an LOD of ~6 fM, within the same time frame of < 30 min observed for specific DNA detection. Our device performance thus exceed those base on 2D materials like Graphene and reduced Graphene oxide, [46][47][48][49] MoS2, 50,51 and even surpasses the performance of InAs and Si nanowire based FET biosensors. 6,[21][22][23] Prior to the nanowire functionalization process, we first optimized and compared the surface coating efficiency and quality of both commonly used aminosilane (APTES) [18][19][20][27][28][29][30] and ethanolamine (EA) alternatives [31][32][33][34] as surface linkers to broad area borosilicate substrates (amorphous SiO2), using the wet chemistry approach.…”

“…The specific interaction measurements follow a saturation behavior for both systems, which can be fitted by Langmuir adsorption isotherms (Figure 6C,F; Figure S6; Supporting Information methods) to gain information about the biosensor sensitivity. 49,[68][69][70] The values obtained for the nonspecific biomolecule titration measurements render the minimal specific detection concentration (MCD), resulting in 7 fM for complementary ssDNA and 32 fM for the IBMP8-1 protein. While such MCDs reflect the lower concentration limits that can be measured with acceptable precision, accuracy and biomarker selectivity, they do not describe the lowest possible concentration detection limit of the analytes.…”

Successive Release of Tissue Inhibitors of Metalloproteinase-1 Through Graphene Oxide-Based Delivery System Can Promote Skin Regeneration

“…Essential characteristics of GO include hydrophobic π domains in the core of the structure with ionized regions along the edges. The distinctive π – π stacking interaction makes GO efficient with water solubility, with a large specific surface area for high loading capacity [ 20 , 21 ].…”