A method of producing electrical power includes: a cathode having a porphyrin precursor attached to a substrate, and having a first enzyme, wherein the first enzyme reduces oxygen; an anode having a first region of an anode substrate and having a gold nanoparticle composition located thereon, and having a second region of the anode substrate having an enzyme composition located thereon, wherein the enzyme composition includes a second enzyme, wherein the first region and second region are separate regions; and a neutral fuel liquid in contact with the anode and cathode, the neutral fuel liquid having a neutral pH and a fuel reagent; and operating the fuel cell to produce electrical power with the neutral fuel liquid having the neutral pH and the fuel reagent.

A method of producing electrical power includes: a cathode having a porphyrin precursor attached to a substrate, and having a first enzyme, wherein the first enzyme reduces oxygen; an anode having a first region of an anode substrate and having a gold nanoparticle composition located thereon, and having a second region of the anode substrate having an enzyme composition located thereon, wherein the enzyme composition includes a second enzyme, wherein the first region and second region are separate regions; and a neutral fuel liquid in contact with the anode and cathode, the neutral fuel liquid having a neutral pH and a fuel reagent; and operating the fuel cell to produce electrical power with the neutral fuel liquid having the neutral pH and the fuel reagent.

An anode can include: an electrode substrate; a first region of the substrate having a catalyst composition located thereon, wherein the catalyst composition includes an inorganic or metallic catalyst; and a second region of the substrate having an enzyme composition located thereon, wherein the combination of the catalyst composition and enzyme composition converts a fuel reagent to carbon dioxide at neutral pH. The first region and second region can be separate regions. The catalyst of the catalyst composition can include gold nanoparticles. The catalyst can include an inorganic or metallic catalyst selected from vanadium oxide, titanium (III) chloride, Pd(OAc).sub.2, MnO, zeolite, alumina, graphitic carbon, palladium, platinum, gold, ruthenium, rhodium, iridium, or combinations thereof. The catalyst can be nanoparticle, nanorod, nanodot, or combination thereof. The catalyst can have sizes that range from about 10 to 20 nm.

A cathode can include: an electrode substrate; a porphyrin precursor attached to the substrate; and an enzyme coupled to the electrode substrate to be associated with the porphyrin precursor, the enzyme reduces oxygen. The cathode can include a conductive material associated with the porphyrin precursor and/or the enzyme. The cathode can include 1-pyrenebutanoic acid, succinimidyl ester (PBSE) associated with the porphyrin precursor and/or the enzyme and/or the conductive material. The cathode can include 2,5-dimethyl-1-phenyl-1H-pyrrole-3-carbaldehyde (DMY-Carb) associated with the 1-pyrenebutanoic acid, succinimidyl ester (PBSE) and/or the porphyrin precursor and/or the enzyme and/or the conductive material. The porphyrin precursor is attached to the substrate through covalent coupling. In some aspects, substrate is linked to the porphyrin precursor, the porphyrin precursor is linked to the conductive material, the conductive material is linked to the PBSE, the PBSE is linked to the DMY-carb, and the DMY-carb is linked to the enzyme.

A cathode can include: an electrode substrate; a porphyrin precursor attached to the substrate; and an enzyme coupled to the electrode substrate to be associated with the porphyrin precursor, the enzyme reduces oxygen. The cathode can include a conductive material associated with the porphyrin precursor and/or the enzyme. The cathode can include 1-pyrenebutanoic acid, succinimidyl ester (PBSE) associated with the porphyrin precursor and/or the enzyme and/or the conductive material. The cathode can include 2,5-dimethyl-1-phenyl-1H-pyrrole-3-carbaldehyde (DMY-Carb) associated with the 1-pyrenebutanoic acid, succinimidyl ester (PBSE) and/or the porphyrin precursor and/or the enzyme and/or the conductive material. The porphyrin precursor is attached to the substrate through covalent coupling. In some aspects, substrate is linked to the porphyrin precursor, the porphyrin precursor is linked to the conductive material, the conductive material is linked to the PBSE, the PBSE is linked to the DMY-carb, and the DMY-carb is linked to the enzyme.

An anode can include: an electrode substrate; a first region of the substrate having a catalyst composition located thereon, wherein the catalyst composition includes an inorganic or metallic catalyst; and a second region of the substrate having an enzyme composition located thereon, wherein the combination of the catalyst composition and enzyme composition converts a fuel reagent to carbon dioxide at neutral pH. The first region and second region can be separate regions. The catalyst of the catalyst composition can include gold nanoparticles. The catalyst can include an inorganic or metallic catalyst selected from vanadium oxide, titanium (III) chloride, Pd(OAc).sub.2, MnO, zeolite, alumina, graphitic carbon, palladium, platinum, gold, ruthenium, rhodium, iridium, or combinations thereof. The catalyst can be nanoparticle, nanorod, nanodot, or combination thereof. The catalyst can have sizes that range from about 10 to 20 nm.