Carbon-Nanotube-Based Monolithic CMOS Platform for Electrochemical Detection of Neurotransmitter Glutamate.

Alexandra Dudina,Andreas Hierlemann,Urs Frey

doi:10.3390/s19143080

Abstract

We present a monolithic biosensor platform, based on carbon-nanotube field-effect transistors (CNTFETs), for the detection of the neurotransmitter glutamate. We used an array of 9′216 CNTFET devices with 96 integrated readout and amplification channels that was realized in complementary metal-oxide semiconductor technology (CMOS). The detection principle is based on amperometry, where electrochemically active hydrogen peroxide, a product of the enzymatic reaction of the target analyte and an enzyme that was covalently bonded to the CNTFET, modulated the conductance of the CNTFET-based sensors. We assessed the performance of the CNTs as enzymatic sensors by evaluating the minimal resolvable concentration change of glutamate in aqueous solutions. The minimal resolvable concentration change amounted to 10 µM of glutamate, which was one of the best values reported for CMOS-based systems so far.

Highlights

The integration of 1D nanomaterials, such as carbon nanotubes (CNT), into sensor array platforms yields a sensitive tool for the detection of biological species and it has significant advantages over conventional optical detection methods [1,2]
We presented a monolithic complementary metal-oxide semiconductor technology (CMOS) system for electrochemical detection of the neurotransmitter glutamate
The system features a large array of carbon-nanotube field-effect transistors (CNTFETs), as well as 96 tunable readout and amplification channels

Summary

Introduction

The integration of 1D nanomaterials, such as carbon nanotubes (CNT), into sensor array platforms yields a sensitive tool for the detection of biological species and it has significant advantages over conventional optical detection methods [1,2]. The second advantage of CNT-based sensor platforms is that most biological processes involve electrostatic interactions and charge transfer, which can be directly detected by charge-sensitive CNTs. In the case of single-walled carbon nanotubes (SWNTs), every atom is at the surface and it is exposed to the environment and, even small changes in the environment can cause significant changes in the nanotube electrical properties [3,4]. Among different nanomaterials, carbon nanotubes have a great potential for biosensor applications

Methods

Results

Conclusion