Large-area, three-dimensional interconnected graphene oxide intercalated with self-doped polyaniline nanofibers as a free-standing electrocatalytic platform for adenine and guanine

Abstract

In this work, we prepared large-area, three-dimensional interconnected graphene oxide (GNO) intercalated by self-doped polyaniline nanofibers (SPAN, a copolymer of aniline and m-aminobenzenesulfonic acid) through a simple adsorption and intercalation route via sonication of the mixed dispersions of both components. The strong p-p* stacking between the backbones of SPAN and the GNO basal planes, and the electrostatic repulsion between the negatively charged SPAN and graphene oxide sheets yield a unique free-standing, three-dimensional interconnected nanostructure. The nanocomposite possesses a large specific surface area and maintains a homogenous and stable dispersion with SPAN, which endows it with a high conductivity and good electrocatalytic activity. Because the negative charge and specific structure of the nanocomposite can prompt the adsorption of positively charged guanine and adenine via strong p-p* interactions or electrostatic adsorption, the hybrid was adopted as an excellent sensing platform for highly sensitive determination of guanine and adenine. The electrocatalytic platform exhibited some advantages, such as high sensitivity, good reproducibility and long-term stability.

Real-time detection of mercury ions in water using a reduced graphene oxide/DNA field-effect transistor with assistance of a passivation layer

“…This sensor enabled real-time sensing for in situ underwater operation; however, the sensor platform could experience inherent performance degradation, such as exhibiting resistor behavior (instead of gate-dependent FET behavior), low sensitivity, and direct immobilization of probes on the rGO surface, which can degrade transistor performance. In addition, rGO has a large surface area and good affinity to probe materials via hydrophobic and π-stacking interactions (He et al 2013b;Li et al 2013;Wang et al 2013;Yang et al 2013), resulting in a loss of probe activity. To improve the performance of rGO-based water sensors, we employed a 2 nmthick Al 2 O 3 film (Figure 1a) fabricated by ALD between the analyte and the active semiconductor layer (rGO) to prevent their direct interaction.…”

The effect of material composition of 3-dimensional graphene oxide and self-doped polyaniline nanocomposites on DNA analytical sensitivity

“…In additional, the reduced graphene nanowalls electrode exhibited an excellent stability with only 15% variation in the oxidation signals after 100 scans [21]. Our group has also reported a simple and lowcost method to prepare large-area, wavy GNO nanowalls intercalated by SPAN (selfdoped polyaniline) [22,23] , where the aggregates of graphite oxide (GO) and SPAN were dispersed through a mixing and sonication process.…”

“…previous reports[22,23] from different mass ratio of GO to SPAN (containing 1:1, 1:2 and 1:3) or different ultrasonication time (including 10 min, 20 min, 30 min and 40 min) to compare their DNA sensing behaviors, shown in Scheme 1. Different nanocomposites have different structures and morphologies inducing the different surface density of the ssDNA and the hybridization efficiency.…”

Three‐Dimensional Graphene‐Based Structures: Production Methods, Properties, and Applications

“…The proposed material exhibited high performance toward electrochemical oxidation of H 2 O 2 with a high sensitivity of 1023.1 μA/mM cm 2 and low detection limit of 0.04 mM. Large-area 3D graphene interconnected GO intercalated by PANI nanofibers for the determination of guanine and adenine have been constructed by Yang et al [120]. By the help of strong π-π interactions and electrostatic adsorption, positively charged guanine and adenine adsorbed to the negatively charged proposed structure.…”