Self‐Assembled Graphene–Enzyme Hierarchical Nanostructures for Electrochemical Biosensing

Abstract

The self‐assembly of sodium dodecyl benzene sulphonate (SDBS) functionalized graphene sheets (GSs) and horseradish peroxidase (HRP) by electrostatic attraction into novel hierarchical nanostructures in aqueous solution is reported. Data from scanning electron microscopy, high‐resolution transmission electron microscopy, and X‐ray diffraction demonstrate that the HRP–GSs bionanocomposites feature ordered hierarchical nanostructures with well‐dispersed HRP intercalated between the GSs. UV‐vis and infrared spectra indicate the native structure of HRP is maintained after the assembly, implying good biocompatibility of SDBS‐functionalized GSs. Furthermore, the HRP–GSs composites are utilized for the fabrication of enzyme electrodes (HRP–GSs electrodes). Electrochemical measurements reveal that the resulting HRP–GSs electrodes display high electrocatalytic activity to H2O2 with high sensitivity, wide linear range, low detection limit, and fast amperometric response. These desirable electrochemical performances are attributed to excellent biocompatibility and superb electron transport efficiency of GSs as well as high HRP loading and synergistic catalytic effect of the HRP–GSs bionanocomposites toward H2O2. As graphene can be readily non‐covalently functionalized by “designer” aromatic molecules with different electrostatic properties, the proposed self‐assembly strategy affords a facile and effective platform for the assembly of various biomolecules into hierarchically ordered bionanocomposites in biosensing and biocatalytic applications.

Organic Solvent-Based Graphene Oxide Liquid Crystals: A Facile Route toward the Next Generation of Self-Assembled Layer-by-Layer Multifunctional 3D Architectures

“…Prior to this work, [47][48][49] the only successful method of increasing the CNT concentration in lyotropic LCs has been through using extensive amounts of surfactants (which can adversely CNTs performance). 50 Only trace amounts of CNTs have been dispersed in thermotropic LCs in order to avoid CNT aggregation. 47,49 However, in our case, we have been able to disperse and organize substantial amounts of SWNTs (up to 10 wt%) in GO LC without losing birefringence properties and observing any aggregation.…”

Direct Electrochemistry and Electrocatalysis of Horseradish Peroxidase Immobilized on Water Soluble Sulfonated Graphene Film via Self‐assembly

“…Because of these exciting properties, GP can greatly improve the performance of electrochemical biosensor and have attracted considerable attention in the field of bioelectrochemistry [14][15][16][17]. So far, several novel mediate-free electrochemical biosensors have been successfully fabricated based on graphene and various redox proteins or enzymes [18][19][20].…”

Graphene and graphene oxide as nanomaterials for medicine and biology application

“…Self-assembling and controllable graphene biomolecules permit assembling ultrasensitive biosensors for recognition of DNA and different atoms [72,73]. GO-based biosensors have been developed by taking advantage of their unique physiochemical properties such as extensive surface region, great electrical conducting ability and the magnificent ability for stacking different biomolecules by means of chemical or physical association [73][74][75].…”