An enzyme logic bioprotonic transducer

Takeo Miyake,Erik E Josberger,Yingxin Deng,Marco Rolandi,Scott Keene

doi:10.1063/1.4900886

Abstract

Translating ionic currents into measureable electronic signals is essential for the integration of bioelectronic devices with biological systems. We demonstrate the use of a Pd/PdHx electrode as a bioprotonic transducer that connects H+ currents in solution into an electronic signal. This transducer exploits the reversible formation of PdHx in solution according to PdH↔Pd + H+ + e−, and the dependence of this formation on solution pH and applied potential. We integrate the protonic transducer with glucose dehydrogenase as an enzymatic and gate for glucose and NAD+. PdHx formation and associated electronic current monitors the output drop in pH, thus transducing a biological function into a measurable electronic output.

Highlights

Translating ionic currents into measureable electronic signals is essential for the integration of bioelectronic devices with biological systems
We demonstrate the use of a Pd/PdHx electrode as a bioprotonic transducer that connects H+ currents in solution into an electronic signal
Ionic species dominate signaling in natural systems, so the conversion of biochemical ionic signals into electronic signals is an essential part of bioelectronics.[1,2,3,4,5,6]

Summary

Introduction

Translating ionic currents into measureable electronic signals is essential for the integration of bioelectronic devices with biological systems. We demonstrate the use of a Pd/PdHx electrode as a bioprotonic transducer that connects H+ currents in solution into an electronic signal. We exploit the electrochemical properties of the formation of PdHx and its dependence on the voltage applied on the contact (Fig. 1).[13,14,15] As a proof of concept, we measure with these devices the pH of a solution modulated by enzymatic reactions, such as the reaction catalyzed by glucose dehydrogenase (GDH) to produce gluconic acid from oxidized nicotinamide adenine dinucleotide (NAD+) and glucose.

Results

Conclusion