Interaction between Biocompatible Graphene Oxide and Live Shewanella in the Self-Assembled Hydrogel: The Role of Physicochemical Properties

Abstract

Understanding the interaction of graphene materials with bacterial cells is crucial for exploiting their environmental applications. Meanwhile, knowledge on the mechanism of graphene oxide (GO) action to bacteria is still incomplete. This study focused on the inter-relationship of biocompatible GO and the well-known dissimilatory metal-reducing bacteria Shewanella, in view of the biographene hydrogel (BGH), a self-assembly of GO and live bacteria. The results showed that, among various inter-related physicochemical properties of GO, the sheet area determined the bacterial survival and the gelation potential with the same Shewanella strain. For the biocompatible GO sheet above 0.30 μm 2 , the larger the GO, the higher the speed of BGH assembling. Only 22 h was needed to obtain BGH using GO with an average area of 1.83 μm 2 (maximum in this study). The GO oxidation degree was found to be another critical factor affecting whether BGH formed or not, with a referential threshold of C/O > 1.75. Finally, surface force of GO was detected and correlated with the bacterial adhesion behavior for the first time, confirming that the large GO in the low oxidation state has high resultant force to attract bacteria. All these findings pave a promising way to develop a GO-bacteria complex like BGH to treat industrial wastewater in the future.

Ultrasensitive detection of aromatic water pollutants through protein immobilization driven organic electrochemical transistors

“…Subsequently, the collected core spectra of C 1s contain three distinct types of carbon peaks at around 284.8 eV (C–C/C C), 287 eV (C–O–C), and 287.4 eV (C O), respectively (Fig. S2B † ) 38 and Fig. S2C † represents the O 1s core spectra of GO sheets.…”

Engineering extracellular electron transfer pathways of electroactive microorganisms by synthetic biology for energy and chemicals production

“…399 Graphene is a highly conductive material and can be used to construct electroactive hybrid biofilms. 366,[400][401][402][403][404][405] Graphene oxide (GO)-modified anodes have a larger surface area and therefore provide more active sites or channels for enhanced electron transfer at the interfaces of EAMs and electrodes. To increase the total loading of the electroactive biofilm on the anode, Yong et al constructed a self-assembled rGO threedimensional heterogeneous biofilms by adding GO in the presence of EAMs, resulting in a highly conductive network in the biofilm matrix and facilitating efficient electron transport between S. oneidensis cells and electrodes.…”

Self-Assembled Biohybrid: A Living Material To Bridge the Functions between Electronics and Multilevel Biological Modules/Systems

“…). − Previously, we have exploited graphene oxide (GO) as a terminal electron acceptor, which can be intimately linked with PV-4 in the form of biologically reduced graphene oxide (B-rGO) via extracellular electron transfer. , In contrast with doped nanomaterials, the B-rGO is closely coupled with the redox-active sites of the biomachinaries through the active bioreduction process and processes a two-dimensional, honeycomb lattice structure at the microscale, which offers unique advantages to host multiple PV-4 cells to construct an integrated network. Together with interactions such as hydrophobic and electrostatic forces, this B-rGO/EAB matrix can self-assemble to form a free-standing three-dimensional (3D) living material with unique electrical/electrochemical activities …”

“…Together with interactions such as hydrophobic and electrostatic forces, this B-rGO/EAB matrix can self-assemble to form a free-standing threedimensional (3D) living material with unique electrical/ electrochemical activities. 27 Here, we exploited this PV-4/B-rGO biohybrid as a unique material platform for creating various living electronic components from the bottom up. First, the self-assembling process was rationally modulated to encode this living material with desirable mechanical integrity, optimal mass/electron transport, and tunable morphology.…”