Real-time electrical detection of nitric oxide in biological systems with sub-nanomolar sensitivity

Abstract

Real-time monitoring of nitric oxide concentrations is of central importance for probing the diverse roles of nitric oxide in neurotransmission, cardiovascular systems and immune responses. Here we report a new design of nitric oxide sensors based on hemin-functionalized graphene field-effect transistors. With its single atom thickness and the highest carrier mobility among all materials, graphene holds the promise for unprecedented sensitivity for molecular sensing. The non-covalent functionalization through p-p stacking interaction allows reliable immobilization of hemin molecules on graphene without damaging the graphene lattice to ensure the highly sensitive and specific detection of nitric oxide. Our studies demonstrate that the graphene-hemin sensors can respond rapidly to nitric oxide in physiological environments with a sub-nanomolar sensitivity. Furthermore, in vitro studies show that the graphene-hemin sensors can be used for the detection of nitric oxide released from macrophage cells and endothelial cells, demonstrating their practical functionality in complex biological systems.

Electrophoretic and field-effect graphene for all-electrical DNA array technology

“…O ver the past couple of decades, electrical detection of biomolecules via their inherent charges has undergone an intense renaissance, with the advent of low-dimensional nanomaterials, such as semiconductor nanowires, carbon nanotubes, and more recently, graphene [1][2][3][4][5][6][7][8] . Configured as field-effect transistors (FETs), these nanomaterials can achieve electrical detection sensitivity down to the picomolar/femtomolar (pM/fM) and even sub-fM level 2,4,[7][8][9][10] .…”

“…Configured as field-effect transistors (FETs), these nanomaterials can achieve electrical detection sensitivity down to the picomolar/femtomolar (pM/fM) and even sub-fM level 2,4,[7][8][9][10] . Given the sensitivity, combined with such advantages as label-free operation and bona fide chip-scale construct, nanomaterial-based electrical biomolecular sensors may one day become an important practical tool in biotechnology.…”

“…This is because the large-area planar morphology of graphene-if, for example, grown by chemical vapour deposition (CVD)-is amenable to top-down fabrication for defining a large array of FET sensor sites 7,12,16 . In fact, graphene FET sensor arrays have been developed for pH monitoring and chemical sensing 6 .…”

Human‐Like Sensing and Reflexes of Graphene‐Based Films

“…In addition, polypyrene (PPr), polypyrrole (PPy) and polyaniline (PANI) were also utilized to form specific selective gas sensor 120, 121, 122. Recently, the real‐time gas sensor of NO has been successfully fabricated to detect the NO with nanomolar sensitivity 123. This gas sensor was based on the hemin‐functionalized graphene field effect transistors ( Figure 12 a,b).…”

“…e–f) Real‐time monitoring of NO released from HUVECs. Reproduced with permission 123. Copyright 2013, Nature Publishing Group.…”