Biofuel enzymatic glucose

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]. 

Zebda (2010) Liquid/liquid Row-by Monolithic Enzymatic biofuel cell Glucose Dissolved O2 0.03 0.55 19... 

Recently, a novel microbial fuel cell harvesting energy from the marine sediment—seawater interface has been reported. Also, a novel photosynthetic biofuel cell that is a hybrid between a microbial and enzymatic biofuel cell has been reported for the very first time. More recently, reports of an unconventional biomass-fueled ceramic fuel cell can also be found in the literature. A new concept of Gastrobots —hybrid robots that utilize operational power derived from microbial fuel cells—has been introduced. Finally, the generation of electrical power by direct oxidation of glucose was demonstrated in mediatorless microbial fuel cells, which produced currents up to 3 fiA/cm at unknown cell voltage. ... 

Fig. 3.1 Schematic representation of an enzymatic biofuel cell design based on the electrical connection of a laccase at the cathode and glucose oxidase at the anode...

The scientific challenge of these enzymatic biofuel cells is to develop devices with compatible power and size to use them as power sources for portable devices such as GPS, mobile phone, MP3 players, or mobile computers. A steady increasing interest within enzymatic biofuel cell design is dedicated to the production of electrical energy from the electro-enzymatic degradation of glucose and O2. These... 

The vast majority of enzyme biofuel cells is based on the electroenzymatic oxidation of glucose by glucose oxidase (GOX) and oxygen reduction by laccase, rarely, bilirubin oxidase, or even ascorbate oxidase. Usually two couples of redox mediators are involved in the functioning of the enzymatic biofuel cell. One is required to establish an electrical connection between the electrode surface and the reduced form of flavin adenine dinucleotide, the prosthetic center of GOX. The second couple, located at the cathode, allows the electron transfer from the electrode siuface to the copper center of laccase where the oxygen reduction takes place (Fig. 3.2). 

Enzymatic bioelectrodes can be coupled in configurations that yield the production of electrical energy from chemical energy, i.e. a biofuel cell (BFC) can be created that produces electricity from fuel and oxidant couples. Perhaps the most commonly reported enzymatic BFCs are fuelled by glucose and utilize oxygen as the oxidant and final electron acceptor. Enzymatic BFCs have been reported which can operate on different fuels sueh as suerose, " trehalose, hydrogen, " and short-chain alcohols. ... 

A schematic for a simple glucose oxidase/bilirubin-based enzymatic biofuel cell. 

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).

Common biochemical pathways for second-generation biofuels include fermentation for the production of ethanol and other alcohols. Fermentation is an anaerobic process where the glucose (or carbohydrates) of organic wastes are converted to ethanol through a series of chemical reactions. A pretreatment step is necessary to increase the yield of sugar, followed by enzymatic hydrolysis and the subsequent fermentation, or by the simultaneous saccharification and fermentation (SSF) process (Romero-Garcia et al., 2014). 

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