Electronic Biosensing with Functionalized rGO FETs.

Ciril Reiner-Rozman,Caroline Kotlowski,Wolfgang Knoll

doi:10.3390/bios6020017

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.

Highlights

The detection and quantitative monitoring of biomolecules in air, in water, in complex liquids like bodily fluids or similar is still a challenge, both from a fundamental point of view as well as in the context of practical applications. Whether it is the need for sensors in general air management scenarios—e.g., to detect air pollutants, to sense crop disease markers, in food quality management for the identification of toxins, or in medical applications like breath analysis—Or for the detection of certain markers in blood, plasma, saliva, urine, wound liquids, etc., that report a patient’s health and/or disease status, in all cases we are dealing with three major problems; (i) the sensitivity of the technical device for the quantification of a particular molecule of interest; (ii) the selectivity needed to differentiate between similar molecules; and (iii) the suppression of non-specific interactions with and binding to the sensor surface by other components in the sample volume, typically in excess to the targeted molecule
Biosensors 2016, 6, 17 monitor action potentials of excited neurons [3] or cardiomyocytes [4] grown on the gate surface of the device, Si-nanowire based transistor read-out of protein and DNA binding [5], or the promising use of organic electronics the development and, sensors
Reduced graphene oxide field-effect transistor devices were fabricated with a Reducedwidth graphene field-effect

Summary

Introduction

The detection and quantitative monitoring of biomolecules in air, in water, in complex liquids like bodily fluids or similar is still a challenge, both from a fundamental point of view as well as in the context of practical applications. The to monitor action potentials for of excited neurons [3] of or cheap cardiomyocytes [4] disposable grown on the gate surface mostofrecent development in based this area, the use of theof novel carbon materials, i.e., nanotubes or the device, Si-nanowire transistor read-out protein and DNA binding [5],carbon or the promising graphene, opens a(“plastic”). Totally new but very range of ofcheap options for biosensors based on electronic use of organic electronics forpromising the development and, disposable sensors [6,7] The most this area, the use of the novel carbon materials, i.e., carbon nanotubes devices maderecent fromdevelopment these highlyininteresting materials [8].

Preparation and General Electronic Performance of rGO-FET Biosensors

Source-drain

Normalized detection of ofAFM1

Outlook