Enzyme-based multiplexer and demultiplexer

A digital 2-to-1 multiplexer and a 1-to-2 demultiplexer were mimicked by biocatalytic reactions involving concerted operation of several enzymes. Using glucose oxidase (GOx) and laccase (Lac) as the data input signals and variable pH as the addressing signal, ferrocyanide oxidation in the output channel was selectively activated by one from two inputs, thus mimicking the multiplexer operation. A demultiplexer based on the enzyme system composed of GOx, glucose dehydrogenase (GDH) and horseradish peroxidase (HRP) allowed selective activation of different output channels (oxidation of ferrocyanide or reduction of NAD⁺) by the glucose input. The selection of the output channel was controlled by the addressing input of NAD⁺. The designed systems represent important novel components of future branched enzyme networks processing biochemical signals for biosensing and bioactuating.