4 research outputs found
All-Photonic Multifunctional Molecular Logic Device
Photochromes are photoswitchable, bistable chromophores which, like transistors, can implement binary logic operations. When several photochromes are combined in one molecule, interactions between them such as energy and electron transfer allow design of simple Boolean logic gates and more complex logic devices with all-photonic inputs and outputs. Selective isomerization of individual photochromes can be achieved using light of different wavelengths, and logic outputs can employ absorption and emission properties at different wavelengths, thus allowing a single molecular species to perform several different functions, even simultaneously. Here, we report a molecule consisting of three linked photochromes that can be configured as AND, XOR, INH, half-adder, half-subtractor, multiplexer, demultiplexer, encoder, decoder, keypad lock, and logically reversible transfer gate logic devices, all with a common initial state. The system demonstrates the advantages of light-responsive molecules as multifunctional, reconfigurable nanoscale logic devices that represent an approach to true molecular information processing units
Realization and Properties of Biochemical-Computing Biocatalytic XOR Gate Based on Enzyme Inhibition by a Substrate
We consider a realization of the XOR logic gate in a process biocatalyzed by
an enzyme (here horseradish peroxidase: HRP), the function of which can be
inhibited by a substrate (hydrogen peroxide for HRP), when the latter is
inputted at large enough concentrations. A model is developed for describing
such systems in an approach suitable for evaluation of the analog noise
amplification properties of the gate. The obtained data are fitted for gate
quality evaluation within the developed model, and we discuss aspects of
devising XOR gates for functioning in "biocomputing" systems utilizing
biomolecules for information processing