Experimental Realization of a High‐Quality Biochemical XOR Gate

Abstract

We report an experimental realization of a biochemical XOR gate function that avoids many of the pitfalls of earlier realizations based on biocatalytic cascades. Inputs-represented by pairs of chemicals-cross-react to largely cancel out when both are nearly equal. The cross-reaction can be designed to also optimize gate functioning for noise handling. When not equal, the residual inputs are further processed to result in the output of the XOR type, by biocatalytic steps that allow for further gate-function optimization. The quality of the realized XOR gate is theoretically analyzed.

Implication and Inhibition Boolean Logic Gates Mimicked with Enzyme Reactions

“…Enzyme‐catalyzed reactions, including sophisticated multi‐step/multi‐enzyme reaction cascades, have been used to mimic almost all known Boolean logic gates, such as Yes (Identity), Not (Inversion), OR, NOR, XOR, NXOR, AND, NAND, INHIB, including reversible logic gates, such as Feynman, Toffoli, Fredkin and Peres gates. While the vast majority of Boolean logic gates mimicked with enzyme systems have been already formulated, optimized and reported for various applications, some unique logic operations still require additional studies. Particularly, Implication (IMPLY) logic gate (also named “material implication”) has not achieved enough attention.…”

Boolean Logic Gates Realized with Enzyme‐catalyzed Reactions – Unusual Look at Usual Chemical Reactions

“…The Boolean XOR logic gate is one of the most important logic elements needed to design complex logic systems performing reversible logic operations and arithmetic functions . Because of its importance, the XOR gate was realized in many different enzyme‐based systems ,. Despite the high interest to the XOR gate, its realization in biocatalytic system is difficult and usually includes an “artificial” assumption – the output signal is frequently considered as the absolute value of the generated signal.…”

“…These systems based on complex biocatalytic cascades and composed of networked logic gates are much more sophisticated. Their optimization (experimental and through theoretical modeling) is not trivial and includes highly sophisticated procedures . Also, the enzyme‐catalyzed binary processes can be used in various biomolecular memory and information security devices.…”

“…Enzyme‐based logic gates are usually realized through relatively simple enzyme‐catalyzed reactions,, Figure . Rapid progress in enzyme‐based information processing systems has resulted in the design of biocatalytic cascades mimicking various Boolean logic gates, including AND,, OR,, NAND, NOR,, CNOT, XOR,,, INHIBIT,, Identity, and Inverter gates. Various reaction cascades have been designed to mimic different combinations of concatenated logic gates, however, they usually do not include more than 3 or 4 logic steps.…”

Nano‐species Release System Activated by Enzyme‐based XOR Logic Gate

“…Indeed, the produced different chemical species, e. g., NAD + and NADH, cannot react in the same way with signal‐responsive materials or stimuli‐activated bioelectronic devices. The problem has been resolved recently by formulating an enzyme‐based XOR gate producing the output species of the same kind . Our recently published report was focused on the formulation and optimization of the novel XOR gate, including the experimental work and theoretical modelling.…”