TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The enzyme immobilized in a non-naturally occurring colloidal immobilization material, which is an acellular, colloidal immobilization material or the micellar or inverted micellar immobilization material, which is a cation-modified perfluoro sulfonic acid-PTFE copolymer. The enzyme comprises an alcohol dehydrogenase, aldehyde dehydrogenase, formate dehydrogenase, formaldehyde dehydrogenase, glucose dehydrogenase, glucose oxidase, lactic dehydrogenase, lactose dehydrogenase or pyruvate dehydrogenase. The enzyme is active for at least 90 days. The cation modified perfluoro sulfonic acid-PTFE copolymer is modified with a hydrophobic cation larger than ammonium ion. The hydrophobic cation comprises an ammonium-based cation, quaternary ammonium cation, alkyltrimethylammonium cation, organic cation, phosphonium cation, triphenylphosphonium, pyridinium cation, imidazolium cation, hexdecylpyridinium, ethidium, viologen, methyl viologen and benzyl viologen, bis(triphenylphosphine)iminium, metal complex, bipyridyl metal complex, phenanthroline-based metal complex, (ruthenium(bipyridine)3)2+ or (iron (phenanthroline)3)3+. The hydrophobic cation comprises a quaternary ammonium cation of formula ((R1)(R2)N+(R3)(R4)). The compounds smaller than the enzymes comprise ammonia, methanol, ethanol, propanol, isobutanol, butanol and isopropanol, allyl alcohols, aryl alcohols, glycerol, propanediol, mannitol, glucuronate, aldehyde, carbohydrates, glucose, glucose-1, D-glucose, L-glucose, glucose-6-phosphate, lactate, lactate-6-phosphate, D-lactate, L-lactate, fructose, galactose-1, galactose, aldose, sorbose, mannose, glycerate, coenzyme A, acetyl coenzyme-A, malate, isocitrate, formaldehyde, acetaldehyde, acetate, citrate, L-gluconate, beta-hydroxysteroid, alpha-hydroxysteroid, lactaldehyde, testosterone, gluconate, fatty acids, lipids, phosphoglycerate, retinal, estradiol, cyclopentanol, hexadecanol, long-chain alcohols, coniferyl-alcohol, cinnamyl-alcohol, formate, long-chain aldehydes, pyruvate, butanal, acyl-coenzyme A, steroids, amino acids, flavin, nicotinamide adenosine dinucleotide, (nicotinamide adenosine dinucleotide)2, nicotinamide adenosine dinucleotide phosphate, (nicotinamide adenosine dinucleotide phosphate)2 or hydrogen. In the salt-extracted tetraalkyl-ammonium modified perfluoro sulfonic acid-PTFE copolymer, the pores are substantially the same size and same shape as the enzyme. The tetraalkyl-ammonium ion comprises an alkyltrimethyl ammonium cation or alkyltriethylammonium cation.R1-R4 = H, hydrocarbyl (optionally substituted) or heterocyclo, preferably H, -CH3, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl or decyl.Provided that at least one of R1-R4 is other than H. EXAMPLE - Tetramethyl ammonium bromide was added to the Nafion (RTM: Sulfonated tetrafluoroethylene based fluoropolymer-copolymer) suspension (5 wt.%) to give mixture-casting solution. The mixture-casting solution (1 ml) was placed in a weighing boat and dried. 18 MW water (7 ml) was added to the weighing boats and allowed to soak overnight. The water was removed and the films were rinsed thoroughly with 18 MW water and dried. The salt-extracted films were then resuspended in methanol (1 ml). Enzyme/Nafion (RTM: Sulfonated tetrafluoroethylene based fluoropolymer-copolymer) casting solutions with an enzyme to tetramethyl ammonium bromide ratio of 2:1 (usually 1200 mu l of 1.0 mu M enzyme: 600 mu l) and nicotinamide adenosine dinucleotide (0.03 g) were vortexed in preparation for coating on electrode. The solution was pipetted onto the electrode, allowed to soak into the carbon-felt electrode and dried.