Ultrasensitive Flexible Graphene Based Field-Effect Transistor (FET)-Type Bioelectronic Nose

Abstract

Rapid and precise discrimination of various odorants is vital to fabricating enhanced sensing devices in the fields of disease diagnostics, food safety, and environmental monitoring. Here, we demonstrate an ultrasensitive and flexible field-effect transistor (FET) olfactory system, namely, a bioelectronic nose (B-nose), based on plasma-treated bilayer graphene conjugated with an olfactory receptor. The stable p- and n-type behaviors from modified bilayer graphene (MBLG) took place after controlled oxygen and ammonia plasma treatments. It was integrated with human olfactory receptors 2AG1 (hOR2AG1: OR), leading to the formation of the liquid-ion gated FET-type platform. ORs bind to the particular odorant amyl butyrate (AB), and their interactions are specific and selective. The B-noses behave as flexible and transparent sensing devices and can recognize a target odorant with single-carbon-atom resolution. The B-noses are ultrasensitive and highly selective toward AB. The minimum detection limit (MDL) is as low as 0.04 fM (10(-15); signal-to-noise: 4.2), and the equilibrium constants of OR-oxygen plasma-treated graphene (OR-OG) and ammonia plasma-treated graphene (-NG) are ca. 3.44 × 10(14) and 1.47 × 10(14) M(-1), respectively. Additionally, the B-noses have long-term stability and excellent mechanical bending durability in flexible systems.

Sensing at the Surface of Graphene Field‐Effect Transistors

“…Looking ahead, new advancements could reside in the development of flexible GFET cellular sensors, [214] by combining the outstanding electronic performances of GFET with the high flexibility of graphene. [215] In such a flexible bioelectronic platform, individual cells in a network can be addressed via electrical interfaces, which could potentially lead to advanced learning circuits, neuron-implants, and neuroprosthesis that could potentially replace damaged nervous tissue for treating brain and paralysis diseases.…”

Organic Bioelectronic Tools for Biomedical Applications

“…Binding of the odorant to the olfactory receptor was translated into a detectable signal specific for the respective odorant. Recently, ultrasensitive carbon nanotube and graphene based electronic noses were developed [74][75][76]. Further, a bioelectronic tongue platform was presented based on a field effect transistor functionalized with human taste receptors [77].…”

Human dopamine receptor nanovesicles for gate-potential modulators in high-performance field-effect transistor biosensors

“…A DA receptor naturally has high selectivity and specificity to DA and belongs to the family of G protein-coupled receptors (GPCRs), which are involved in important physiological processes, including neuronal transmission, sensory signaling, and hormone signaling [23][24][25] . Recently, GPCRs as recognizing elements in FET system allowed high selectivity for the detection of specific ligands and the development of biosensors based on nanomaterial-based geometries 24,[26][27][28][29] .…”

“…Recently, GPCRs as recognizing elements in FET system allowed high selectivity for the detection of specific ligands and the development of biosensors based on nanomaterial-based geometries 24,[26][27][28][29] . However, those protein-attached biosensors using GPCRs as recognition elements cannot mimic the GPCR-mediated intracellular signal transduction 30 .…”