Advances on the Use of Graphene as a Label for Electrochemical Biosensors

Abstract

There has been an overwhelming interest in the use of graphene and its derivatives for electrochemical biosensors in the last decade. Although the majority of the works describe the use of these materials as platform for the immobilization of the biorecognition element, there is a significant, often unrecognized, research effort that has shown how graphene materials can also beneficially serve as signaling labels for biosensing. Owing to its intrinsic electroactivity and small size, nano‐graphene oxide, for example, has been used for this purpose, where the working signal arises from the reduction of the oxygen functionalities on the material surface. In other approaches, graphene labels modified with electroactive probes were also used to promote the signal generation. This Minireview will illustrate how the unique electrochemical and structural features make graphene a very promising material for the detection of the biorecognition event. In addition, an overview will be provided, showing the plethora of options offered by graphene and its derivatives as labels for signal generation and enhancement.

Electrochemical Signal Amplification Strategies and Their Use in Olfactory and Taste Evaluation

“…In electrochemical enzyme biosensors, GR was shown to not only connect an electrode surface to an enzyme to achieve electron transfer, but was also shown to enhance the electrochemical signal response [ 96 ]. In addition, GR and its related materials can be used as a direct marker in immunoassays using a working signal generated by the reduction of its oxygen-containing groups, or they can rely on the modification of this working signal with other electroactive probes to generate an indirect marker [ 97 , 98 ]. Bonanni et al [ 68 ] constructed an electrochemical biosensor using GO as a direct marker for the detection of DNA polymorphisms.…”

Ultrasensitive Materials for Electrochemical Biosensor Labels

“…These unique features also make them promising signaling labels for bio-recognition events in biosensing applications. Graphene and related materials can serve as a “Direct label” or “Indirect label” for signal generation in immunoassays [ 62 ]. The direct labeling strategy exploits the working signal generated from the reduction of the oxygen-containing groups, whereas the indirect label strategy relies on the graphene labels modified with other electroactive probes for the generation of working signal [ 57 ].…”