Tuning the Electrical Properties of Electrospun Nanofibers with Hybrid Nanomaterials for Detecting Isoborneol in Water Using an Electronic Tongue

Fernanda L Migliorini,Luiz H C Mattoso,Kelcilene B R Teodoro,Fernando J Fonseca,Danilo M Dos Santos,Daniel S Correa,Vanessa P Scagion

doi:10.3390/surfaces2020031

Abstract

The presence of contaminants in water is a subject of paramount importance nowadays, which can make water improper to human consumption even when these contaminants are present at very low concentrations, causing health issues and economic losses. In this work, we evaluated the performance of nanocomposites based on nylon 6,6/chitosan electrospun nanofibers modified by cellulose nanowhiskers combined with functional materials like silver nanoparticles, gold nanoparticles, and reduced graphene oxide to be used as sensing layers of an electronic tongue (e-tongue) to detect Isoborneol. This compound, found in some plants and essential oils, is used as a natural repellent and also to produce many other chemicals. Additionally, its chemical structure is related to that of 2-methylisoborneol, a critical pollutant in aqueous media. The synergism between the nanomaterials combined with electrospun nanofibers could be verified by the enhancement of the charge transference ability. Additionally, electrical capacitance data measured with the impedimetric e-tongue were treated by Principal Component Analysis (PCA), and revealed the sensing system was able to discriminate samples contaminated with Isoborneol at nanomolar concentrations. Moreover, the electronic tongue system could detect Isoborneol in real water samples under different concentrations.

Highlights

The monitoring of distributed domestic-water quality attracts great attention since it usually originates from rivers, lakes, and dams, and may contain different types of residues [1,2].The chemical nature of these residues can range from dissolved salts, nutrients, microorganisms, or contaminants like heavy metals, pesticides, and hormones, among others
Commercial white cotton from Apolo (Palmeiras, Brazil), sulfuric acid, sodium citrate, and formic acid were purchased from Labsynth Chemical (São Paulo, Brazil)
Chitosan was prepared by applying the ultrasound-assisted deacetylation (USAD) process to β-chitin extracted from squid pens, according to Fiamingo and Campana Filho [33]

Summary

Introduction

The chemical nature of these residues can range from dissolved salts, nutrients, microorganisms, or contaminants like heavy metals, pesticides, and hormones, among others. Some of these compounds can lead to the proliferation of algae, such as cyanobacteria, which are considered toxic, depending on the concentration [3]. Surfaces 2019, 2 treatment of cardiovascular diseases [10], and as a natural repellent [11]. The presence of these compounds in drinking water monitored and controlled by highly easy of cardiovascular diseases [10], andmust as a be natural repellent [11].

Methods

Results

Conclusion