Biomolecular AND Logic Gate Based on Immobilized Enzymes with Precise Spatial Separation Controlled by Scanning Electrochemical Microscopy

Abstract

A surface-localized enzymatic AND gate based on scanning electrochemical microscopy was designed and studied. The gate is composed of an insulating glass surface modified with the enzyme glucose oxidase (GOx) and another surface opposing it made of a microelectrode. The latter was modified with a second enzyme, invertase (INV). The distance separating the modified microelectrode and surface controlled the output of the AND gate produced upon the biocatalytic reaction of the confined enzymes. Specifically, as the GOx-modified glass substrate entered the diffusion layer of the microelectrode, it catalyzed the regeneration of an electron-transfer mediator, ferroceniummethanol, generated electrochemically at the tip by oxidizing glucose, also generated at the tip, by catalytic cleaving of sucrose by INV. To enhance the activity of the GOx, mutarotase was added to convert α- to β-glucose to be further consumed by GOx. Hence, an increase of the current at the microelectrode was obtained by approaching the glass surface only in the presence of all the components. This is the first micrometer-sized biomolecular logic gate, of which we are aware, that is surface-confined and shows the promise held by the localization of biomolecular information-processing species.

Majority and Minority Gates Realized in Enzyme-Biocatalyzed Systems Integrated with Logic Networks and Interfaced with Bioelectronic Systems

“…While computational applications of biomolecular systems 14−16 competing with modern electronics are rather futuristic, their use in low scale information processing for biosensing 17−19 and bioactuating, 20−22 particularly aiming at medical use 23−26 and operation in a biological environment, 27,28 is already feasible at the present level of technology. Rapid progress in enzyme-based information processing systems resulted in the design of biocatalytic cascades mimicking various Boolean logic gates, 1 including AND, [29][30][31][32][33][34][35][36]34,36,37 NAND,38,39 NOR,36,39 CNOT, 40 XOR,34,36,41,42 INHIBIT,34,36 Identity, 36 and Inverter 36 gates. Assembling enzyme logic gates in complex networks composed of several concatenated gates resulted in an increased complexity of the information processing systems.…”

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

“…The Boolean AND logic gate is one of the most frequently designed systems (along with the OR gate which is also very common), particularly realized with enzyme‐catalyzed reactions ,,,,. While the OR logic gate, discussed earlier, can be easily realized with two biocatalytic reactions operating in parallel, the AND gate is often designed to operate as a cascade of two consecutive biocatalytic processes, Figure A.…”

Fabrication of Electrochemical-Based Bioelectronic Device and Biosensor Composed of Biomaterial-Nanomaterial Hybrid

“…However, in recent years, biomolecules have been recognized as a logic component because of the new advantages compared to conventional logic devices. The first advantage is that biomolecules can offer the possibility of homogeneous system fabrication to develop the uniform threedimensional logic system compared to two-dimensional solid-state device which is widely used (Gdor et al 2013). Thus, biomolecules-based system can provide the integration of complex reacting process for the development of high-order logic gate (Katz 2015).…”