Boosting Selectivity and Sensitivity to Biomarkers of Quantum Resistive Vapour Sensors Used for Volatolomics with Nanoarchitectured Carbon Nanotubes or Graphene Platelets Connected by Fullerene Junctions

Sananda Nag,Jean-Francois Feller,Veena Choudhary,Mickaël Castro

doi:10.3390/chemosensors9040066

Abstract

Nanocarbon-based vapour sensors are increasingly used to make anticipated diagnosis of diseases by the analysis of volatile organic compound (VOC) biomarkers from the breath, i.e., volatolomics. However, given the tiny number of molecules to detect, usually only tens of parts per billion (ppb), increasing the sensitivity of polymer nanocomposite chemoresistive transducers is still a challenge. As the ability of these nanosensors to convert the interactions with chemical compounds into changes of resistance, depends on the variations of electronic transport through the percolated network of the conducting nanofillers, it is a key parameter to control. Actually, in this conducting architecture, the bottlenecks for electrons’ circulation are the interparticular junctions giving either ohmic conduction in the case of close contacts or quantum tunnelling when jumps though gaps are necessary. This in turn depends on a number of nanometric parameters such as the size and geometry of the nanofillers (spherical, cylindrical, lamellar), the method of structuring of the conductive architecture in the sensory system, etc. The present study focuses on the control of the interparticular junctions in quantum-resistive vapour sensors (vQRS) by nanoassembling pristine CNT or graphene covalently or noncovalently functionalized with spherical Buckminster fullerene (C60) into a percolated network with a hybrid structure. It is found that this strategy allows us to significantly boost, both selectivity and sensitivity of pristine CNT or graphene-based transducers exposed to a set of seven biomarkers, ethanol, methanol, acetone, chloroform, benzene, toluene, cyclohexane and water. This is assumed to result from the spherical fullerene acting on the electronic transport properties at the nanojunctions between the CNT or graphene nanofillers.

Highlights

The demand for the development of miniaturized sensors arrays for fast, low-cost, low-power detection and discrimination of volatile organic compounds (VOC) has increased dramatically over the years
The three-dimensional Atomic Force Microscopy (AFM) images of pristine Carbon nanotubes (CNT), Graphene oxide (GO) and C60 are exhibited in Figure 2a–c, respectively
It has been assumed that the enhancement of the electronic mobility through the CNT or graphene network, due to the grafting at junctions of spherical Buckminster fullerene with high surface area, is the most likely reason for the important gain of sensing properties obtained

Summary

Introduction

The demand for the development of miniaturized sensors arrays for fast, low-cost, low-power detection and discrimination of volatile organic compounds (VOC) has increased dramatically over the years. The spheres of application of VOC sensing beyond medicine are food degradation monitoring [20,21,22], environment monitoring, i.e., the indication of hazardous chemical leakage, the monitoring of organic 4.0/). Chemosensors 2021, 9, 66 solvent vapour concentration in the air [23,24,25,26], space exploration, and homeland security [27,28,29,30], process control of chemical and food production [31], the monitoring of quality and alcohol content in automotive fuel [32,33] and others [34]. Nanomaterials belonging to fullerene family are already proved to act as a well-recognized component for elaboration of VOC sensors

Methods

Results

Conclusion