A Light-Driven Integrated Bio-Capacitor with Single Nano-Channel Modulation

Jie Lin,Yu-Tao Li,Lei Han,Xiao-Xing Xing,Yu-Jia Lv,Kuan Sun,Yan Xiang

doi:10.3390/nano12040592

Abstract

Bioelectronics, an emerging discipline formed by the biology and electronic information disciplines, has maintained a state of rapid development since its birth. Amongst the various functional bioelectronics materials, bacteriorhodopsin (bR), with its directional proton pump function and favorable structural stability properties, has drawn wide attention. The main contents of the paper are as follows: Inspired by the capacitive properties of natural protoplast cell membranes, a new bio-capacitor based on bR and artificial nanochannels was constructed. As a point of innovation, microfluidic chips were integrated into our device as an ion transport channel, which made the bio-capacitor more stable. Meanwhile, a single nanopore structure was integrated to improve the accuracy of the device structure. Experiments observed that the size of the nanopore affected the ion transmission rate. Consequently, by making the single nanopore’s size change, the photocurrent duration time (PDT) of bR was effectively regulated. By using this specific phenomenon, the original transient photocurrent was successfully transformed into a square-like wave.

Highlights

With the rapid development of bioelectronics [1,2,3,4,5,6,7], increasing numbers of bioelectronic devices have been developed and widely used
Bacteriorhodopsin extracted from Halobacterium halobium is a new type of biological material, which is widely used in bioelectronic devices
A microfluidic channel is used to transport H+ ions, while fabricated nanopores are integrated into the device upon the microfluidic channel to control the rate of diffusion of H+ ions

Summary

Introduction

With the rapid development of bioelectronics [1,2,3,4,5,6,7], increasing numbers of bioelectronic devices have been developed and widely used. BR has many excellent material properties such as a higher light cycle stability [19], pH tolerance [20], thermal stability [19], and chemical stability [21], which improves its functional activity in the fabrication of bioelectronic devices outside the cell Based on these material properties and the advantages of bR described above, it has been applied in a variety of bioelectronic devices, such as artificial retinal prosthesis [22], optical storage [23,24,25], photovoltaic cells [26], and pH sensors [27,28,29]. The regulation of photocurrent shape can be achieved by some basic electronic components (e.g., capacitors), which greatly

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Discussion

Conclusion