A wireless transmission system powered by an enzyme biofuel cell implanted in an orange.

A biofuel cell composed of catalytic electrodes made of "buckypaper" modified with PQQ-dependent glucose dehydrogenase and FAD-dependent fructose dehydrogenase on the anode and with laccase on the cathode was used to activate a wireless information transmission system. The cathode/anode pair was implanted in orange pulp extracting power from its content (glucose and fructose in the juice). The open circuit voltage, Voc, short circuit current density, jsc, and maximum power produced by the biofuel cell, Pmax, were found as ca.

Self-powered electrochemical memristor based on a biofuel cell--towards memristors integrated with biocomputing systems.

The electrochemical memristor based on a pH-switchable polymer-modified electrode integrated with a biofuel cell was designed and proposed for interfacing between biomolecular information processing and electronic systems. The present approach demonstrates a new application of biofuel cells in information processing systems, rather than for electrical power generation.

A bioinspired associative memory system based on enzymatic cascades.

A biomolecular system representing the first realization of associative memory based on enzymatic reactions in vitro has been designed. The system demonstrated "training" and "forgetting" features characteristic of memory in biological systems, but presently realized in simple biocatalytic cascades.

A pacemaker powered by an implantable biofuel cell operating under conditions mimicking the human blood circulatory system--battery not included.

Biocatalytic electrodes made of buckypaper were modified with PQQ-dependent glucose dehydrogenase on the anode and with laccase on the cathode and were assembled in a flow biofuel cell filled with serum solution mimicking the human blood circulatory system. The biofuel cell generated an open circuitry voltage, Voc, of ca. 470 mV and a short circuitry current, Isc, of ca.

Electrode interfaces switchable by physical and chemical signals for biosensing, biofuel, and biocomputing applications.

This review outlines advances in designing modified electrodes with switchable properties controlled by various physical and chemical signals. Irradiation of the modified electrode surfaces with various light signals, changing the temperature of the electrolyte solution, application of a magnetic field or electrical potentials, changing the pH of the solutions, and addition of chemical/biochemical substrates were used to change reversibly the electrode activity. The increasing complexity in the signal processing was achieved by integration of the switchable electrode interfaces with biomolecular information processing systems mimicking Boolean logic operations, thus allowing activation and inhibition of electrochemical processes on demand by complex combinations of biochemical signals.

Enzyme-based D-flip-flop memory system.

The enzyme system was used to mimic the D-flip-flop memory unit. The reversible conversion of NAD(+) and NADH cofactors was used to encode the states of the memory unit, while a mixture of inhibitors was used as the Clock input and the substrates were used as the Data input.

Realization of Associative Memory in an Enzymatic Process: Toward Biomolecular Networks with Learning and Unlearning Functionalities.

We report a realization of an associative memory signal/information processing system based on simple enzyme-catalyzed biochemical reactions. Optically detected chemical output is always obtained in response to the triggering input, but the system can also "learn" by association, to later respond to the second input if it is initially applied in combination with the triggering input as the "training" step. This second chemical input is not self-reinforcing in the present system, which therefore can later "unlearn" to react to the second input if it is applied several times on its own.

Set-reset flip-flop memory based on enzyme reactions: toward memory systems controlled by biochemical pathways.

The enzyme-based set-reset flip-flop memory system was designed with the core part composed of horseradish peroxidase and diaphorase biocatalyzing oxidation and reduction of redox species (2,6-dichloroindophenol or ferrocyanide). The biocatalytic redox reactions were activated by H(2)O(2) and NADH produced in situ by different enzymatic reactions allowing transformation of various biochemical signals (glucose, lactate, d-glucose-6-phosphate, ethanol) into reduced or oxidized states of the redox species. The current redox state of the system, controlled by the set and reset signals, was read out by optical and electrochemical means.