Direct Electrochemistry of <I>Shewanella Loihica</I> PV-4 on Gold Nanoparticles-Modified Boron-Doped Diamond Electrodes Fabricated by Layer-by-Layer Technique

Abstract

Microbial Fuel Cells (MFCs) are robust devices capable of taping biological energy, converting pollutants into electricity through renewable biomass. The fabrication of nanostructured electrodes with good bio- and electrochemical activity, play a profound role in promoting power generation of MFCs. Au nanoparticles (AuNPs)-modified Boron-Doped Diamond (BDD) electrodes are fabricated by layer-by-layer (LBL) self-assembly technique and used for the direct electrochemistry of Shewanella loihica PV-4 in an electrochemical cell. Experimental results show that the peak current densities generated on the Au/PAH multilayer-modified BDD electrodes increased from 1.25 to 2.93 microA/cm(-2) as the layer increased from 0 to 6. Different cell morphologies of S. loihica PV-4 were also observed on the electrodes and the highest density of cells was attached on the (Au/PAH)6/BDD electrode with well-formed three-dimensional nanostructure. The electrochemistry of S. loihica PV-4 was enhanced on the (Au/PAH)4/BDD electrode due to the appropriate amount of AuNPsand thickness of PAH layer.

Controlled Layer-By-Layer Deposition of Carbon Nanotubes on Electrodes for Microbial Fuel Cells

“…Energies 2017, 10, x FOR PEER REVIEW 7 of 16 performance. These results were similar to reported results that the current density generated by S. loihica PV-4 was improved on the (Au/PAH)4/BDD electrode [37], (Fe2O3/CS)4/ITO electrode [38] and ITO/(PAH/GE)2 electrode [35] due to the appropriate amount of Au nanoparticles, Fe2O3 nanorods, graphene and thickness of PAH and chitosan. However, with respect to the current densities generated on other electrode materials-such as the (CNTs/PANI)12/APTES/ITO electrode (70.3 mA/m 2 ) [36], graphite electrode (585 mA/m 2 ) and CNT-coated graphite electrode (1429 mA/m 2 ) [26]that of the (CNTs/PAH)9-ITO electrode was unsatisfied, probably due to the increase of electron's pathway distance between microbe and electrode, caused by the insulated PAH.…”

Novel Aspects of Diamond

“…In mice, intravenous injection of 50 nm NDs led to long-term entrapment in the liver and the lung [195], but no mice showed any abnormal symptoms. Similarly, subcutaneous and intraperitoneal injection of 100 nm NDs in rats led to accumulation of NDs in retention organs over 1 month with no impact on the rats' viability [197]. However, a slight surface-dependent genotoxicity of NDs was recently reported on embryonic stem cells [199].…”

“…Several long-term in vitro [22,194] and in vivo [195][196][197] previous studies demonstrated that NDs are non-cytotoxic, better tolerated by cells than other nanocarbon materials [198]. NDs introduced into Caenorhabditis elegans worm did not cause any detectable stress to worms [198].…”

“…Several reports exist showing the effectiveness of nickel and nickel hydroxide nanoparticles for glucose oxidase sensing [56,196]. An array of self-assembled Au nanoparticles has been able to engage in direct electrochemistry with a microbe, thus suggesting more exotic use of diamond within microbial fuel cells [197]. Many reviews exist on this topic, and a selection is provided here [4,12,15,20,72,198].…”

“…Various attempts are being made to address one or both of these issues by the following approaches: nano-structuring diamond [205][206][207][208], synthesizing new diamond-based nanoparticles (e.g. nanowires [209][210][211], nanograss [212]), grafting diamond nanoparticles [213,214], micro-contact printing of diamond nanoparticles to surfaces [143], and the self-assembly of nanoparticles [197,[215][216][217]. The stabilization of nanoparticles with electropolymers continues to be a fruitful area of research, particularly for bio-applications [139][140][141][142]193].…”