Solution Chemistry of Self-Assembled Graphene Nanohybrids for High-Performance Flexible Biosensors

Abstract

We report the preparation of free-standing flexible conductive reduced graphene oxide/Nafion (RGON) hybrid films by a solution chemistry that utilizes self-assembly and directional convective-assembly. The hydrophobic backbone of Nafion provided well-defined integrated structures, on micro- and macroscales, for the construction of hybrid materials through self-assembly, while the hydrophilic sulfonate groups enabled highly stable dispersibility ( approximately 0.5 mg/mL) and long-term stability (2 months) for graphene. The geometrically interlocked morphology of RGON produced a high degree of mechanical integrity in the hybrid films, while the interpenetrating network constructed favorable conduction pathways for charge transport. Importantly, the synergistic electrochemical characteristics of RGON were attributed to high conductivity (1176 S/m), facilitated electron transfer (ET), and low interfacial resistance. Consequently, RGON films obtained the excellent figure of merit as electrochemical biosensing platforms for organophosphate (OP) detection, that is, a sensitivity of 10.7 nA/microM, detection limit of 1.37 x 10(-7) M, and response time of <3 s. In addition, the reliability of RGON biosensors was confirmed by a fatigue test of 100 bending cycles. The strategy described here provides insight into the fabrication of graphene and hybrid nanomaterials from a material perspective, as well as the design of biosensor platforms for practical device applications.

Fabrication and Characterization of Electrospun PHA/Graphene Silver Nano-Composite Scaffold for Antibacterial Application

“…The maximum weight loss was observed from 250°C to 400°C for both rGO (38%) and GAg (28%) which may be due to the loss of left over oxygen functional group and bulk pyrolysis of the carbon skeleton. TGA curves of rGO and GAg exhibit a slight mass loss at temperature around 600°C, which suggests that the enhancement of thermal stability is achieved after the oxygen-containing functional groups were removed during reduction [59,60]. TGA results of GAg showed better thermal stability as compare to rGO alone.…”

Graphene based biosensors—Accelerating medical diagnostics to new-dimensions

“…[79][80][81] However, LB technique is the most promising alternating method to assemble amphiphilic molecules at the air-water interface as it enables precise control over the monolayer thickness and gap between them, providing homogeneous deposition of the monolayer over large areas and could be useful to make hybrid films with varying layer composition. [82][83][84][85][86] Furthermore, lithography and various printing strategies have also been used for patterning graphene that have been acquired from the CVD method for sensing application. 87,88 C. 2D hybrid and 3D graphene materials Fusion of NP or polymer with graphene offers individual properties of each material in one hybrid material.…”

Synthesis and 3D-AFM surface topology of nanographene-like material extracted from sulfonated tri-, di- and monochloroacetic acid

“…Several methods for the preparation of graphite oxide have been reported [14][15][16][17][18]. Hummers' original method has been modified in several ways to increase the degree of oxidation of graphite.…”

“…Hummers' original method has been modified in several ways to increase the degree of oxidation of graphite. Pre-oxidized graphite has also been used to prepare graphite oxide by the modified Hummers' method [15]. The Staudenmaier method is also an effective way to produce chemically oxidized graphite.…”