Biologically templated assembly of hybrid semiconducting nanomesh for high performance field effect transistors and sensors.

Hye-Hyeon Byeon,Hyunjung Yi,Seung-Woo Lee,Eun-Hee Lee,Woong Kim

doi:10.1038/srep35591

Abstract

Delicately assembled composites of semiconducting nanomaterials and biological materials provide an attractive interface for emerging applications, such as chemical/biological sensors, wearable health monitoring devices, and therapeutic agent releasing devices. The nanostructure of composites as a channel and a sensing material plays a critical role in the performance of field effect transistors (FETs). Therefore, it is highly desirable to prepare elaborate composite that can allow the fabrication of high performance FETs and also provide high sensitivity and selectivity in detecting specific chemical/biological targets. In this work, we demonstrate that high performance FETs can be fabricated with a hydrodynamically assembled composite, a semiconducting nanomesh, of semiconducting single-walled carbon nanotubes (S-SWNTs) and a genetically engineered M13 phage to show strong binding affinity toward SWNTs. The semiconducting nanomesh enables a high on/off ratio (~104) of FETs. We also show that the threshold voltage and the channel current of the nanomesh FETs are sensitive to the change of the M13 phage surface charge. This biological gate effect of the phage enables the detection of biologically important molecules such as dopamine and bisphenol A using nanomesh-based FETs. Our results provide a new insight for the preparation of composite material platform for highly controllable bio/electronics interfaces.

Highlights

Since potential is directly related to the surface charge density and the M13 phage is directly interfacing with the semiconducting single-walled carbon nanotubes (SWNTs)- channel, the M13 phage can behave as local gate that is sensitive to local charge density via change of pH or binding of small molecules, as schematically illustrated in Fig. 1d and demonstrated further below[33]
The exquisite assembly of the individual semiconducting-enriched SWNTs (S-SWNTs) and M13 phages can lead to the fabrication of high-performance FETs (Ion/Ioff ~ 104) without relying on lithographic, chemical or annealing processes
Demonstration of high performance FETs indicates that the S-SWNTs can be effectively dispersed in the nanomesh via hydrodynamic process in which bundle formation or defect generation is minimized

Summary

Introduction

A biological template material encoded with specific binding affinity toward nanoscale electronic materials could serve as an ideal platform to assemble nanoscale semiconducting material and at the same time confer additional functionality for highly controllable electrochemical interfaces. We demonstrate that high quality semiconducting nanomesh can be fabricated based on the genetically engineered filamentous biological template, M13 phage, and semiconducting-enriched SWNTs (S-SWNTs). The semiconducting nanomesh-based FETs are sensitive to the change of the local charge density and pH via the biological gate effect of the phage. This charge sensitive nature allows the semiconducting nanomesh-based electrolyte-gated FETs (e-FETs) to detect important biological chemicals such as dopamine and bisphenol A. We envision that the biologically integrated semiconducting nanomesh would serve as a new material platform for highly controllable bio/electronics interfaces and flexible biosensors

Methods

Results

Conclusion