Assembled biofuel cells

Indeed, in a preli rni nary study we reported a comparison of ORR currents observed 

Melanocarpus alhomyces laccases [148], with highest ORR current density observed 

A series of reports, focused on systematic approaches to optimizing choice of biocatalyst and either redox polymer-based mediator and/or carbon-based support, to provide for a glucose-oxygen EFC are noteworthy for the wide-ranging 

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Moreover, it has been demonstrated that CNTs promote the direct electrochemistry of enzymes. Dong and coworkers have reported the direct electrochemistry of microperoxidase 11 (MP-11) using CNT-modified GC electrodes [101] and layer-by-layer self-assembled films of chitosan and CNTs [102], The immobilized MP-11 has retained its bioelectrocatalytic activity for the reduction of H202 and 02, which can be used in biosensors or biofuel cells. The direct electrochemistry of catalase at the CNT-modified gold and GC electrodes has also been reported [103-104], The electron transfer rate involving the heme Fe(III)/Fe(II) redox couple for catalase on the CNT-modified electrode is much faster than that on an unmodified electrode or other... 

Biofuel cells based on wired enzyme assemblies... 

Mediated enzyme electrodes were also realized on combined microscale and nanoscale supports [300]. Bioelectrocatalytic hydrogels have also been realized by co-assembling electron-conducting metallopolypeptides with bifunctional building blocks [301]. More recently, redox-modified polymers have been employed to build biofuel cells [25, 70, 302, 303]. In 2003, an enzymatic glucose/02 fuel cell which was implanted in a living plant was introduced [147]. 

The need to improve the electrical communication between redox proteins and electrodes, and the understanding that the structural orientation at the molecular level of redox proteins and electroactive relay units on the conductive surfaces is a key element to facilitate ET, introduced tremendous research efforts to nano-engineer enzyme electrodes with improved ET functionalities. The present chapter addresses recent advances in the assembly of structurally aligned enzyme layers on electrodes by means of surface reconstitution and surface crosslinking of structurally oriented enzyme/cofactor complexes on electrodes. The ET properties of the nano-structured interfaces is discussed, as well as the possible application of the systems in bioelectronic devices such as biosensors, biofuel cell elements or optical and electrical switches. 

Saleh, F.S., Mao, L., Ohsaka, T. Development of a dehydrogenase-based glucose anode using a molecular assembly composed of nile blue and functionalized SWCNTs and its applications to a glucose sensor and glucose/02 biofuel cell Sens. Actuators B 152(1), 130-135 (2011). doi 10.1016/j.snb.2010.07.054... 

Biofuel Cells Based on Wired Enzyme Assemblies... 

Fig. 22 (A) Graphene based membrane-less enzymatic biofuel cell components. (B) (a) Current-voltage behaviours of ( ) graphene based EBFC and (A ) SWCNT based EBFC with different external loads in 100 niM glucose solution, (b) power densities at different cell voltage for ( ) graphene based EBFC and (A) SWCNT based EBFC in 100 mM glucose solution, (c) stability of the assembled graphene based EBFC as a function of time. The external load in the test was 15 k i. Other conditions are the same as those in (a) and (b) (reprint permission from ref. 83).

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