Sensors

Editorial

Jump to: Research, Review

3 pages, 151 KiB

Open AccessEditorial

Applications of Graphene-Based Materials in Sensors

by Miguel Hernaez

Sensors 2020, 20(11), 3196; https://doi.org/10.3390/s20113196 - 4 Jun 2020

Cited by 44 | Viewed by 4538

Abstract

This Special Issue compiles a set of innovative developments on the use of graphene-based materials in the fabrication of sensors. In particular, these contributions report original studies on a wide variety of sensors, such as gas sensors for NO₂ or NH₃ [...] Read more.

This Special Issue compiles a set of innovative developments on the use of graphene-based materials in the fabrication of sensors. In particular, these contributions report original studies on a wide variety of sensors, such as gas sensors for NO₂ or NH₃ detection, antibody biosensors or mass sensors. All these devices have one point in common: they have been built using graphene-based materials like graphene, graphene oxide, reduced graphene oxide, inkject printing graphene, graphene-based composite sponges, graphene screen-printed electrodes or graphene quantum dots. Full article

(This article belongs to the Special Issue Applications of Graphene-Based Materials in Sensors)

Research

Jump to: Editorial, Review

17 pages, 3816 KiB

Open AccessArticle

Mechanical, Electrical, and Piezoresistive Sensing Characteristics of Epoxy-Based Composites Incorporating Hybridized Networks of Carbon Nanotubes, Graphene, Carbon Nanofibers, or Graphite Nanoplatelets

by XiaoDong Wang, JianChao Wang, Swarup Biswas, Hyeok Kim and IlWoo Nam

Sensors 2020, 20(7), 2094; https://doi.org/10.3390/s20072094 - 8 Apr 2020

Cited by 23 | Viewed by 3244

Abstract

The present study compared the mechanical, electrical, morphological, and piezoresistive characteristics of epoxy-based sensing nanocomposites fabricated with inclusions of hybridized networks of four different carbon nanomaterials (CNMs), such as carbon nanotube (CNT), graphene, carbon nanofiber (CNF), and graphite nanoplatelet (GNP). Enhancements in elastic [...] Read more.

The present study compared the mechanical, electrical, morphological, and piezoresistive characteristics of epoxy-based sensing nanocomposites fabricated with inclusions of hybridized networks of four different carbon nanomaterials (CNMs), such as carbon nanotube (CNT), graphene, carbon nanofiber (CNF), and graphite nanoplatelet (GNP). Enhancements in elastic modulus and electrical conductivity were achieved by CNT–graphene composites and CNT–CNF composites, and these were explained by the morphological observations carried out in the present study and experimental studies found in the literature. The greatest gauge factor was accomplished by the CNT–GNP composite, followed by the CNT–CNF composite among composites where the CNM networks were sufficiently formed with a content ratio of 3%. The two types of the composites outperformed the composites incorporating solely CNT in terms of gauge factor, and this superiority was explained with the excluded volume theory. Full article

(This article belongs to the Special Issue Applications of Graphene-Based Materials in Sensors)

► Show Figures

Figure 1

13 pages, 4087 KiB

Open AccessArticle

Multifunctional Graphene-Based Composite Sponge

by Xu Cui, Jiayu Tian, Yin Yu, Aron Chand, Shuocheng Zhang, Qingshi Meng, Xiaodong Li and Shuo Wang

Sensors 2020, 20(2), 329; https://doi.org/10.3390/s20020329 - 7 Jan 2020

Cited by 12 | Viewed by 3332

Abstract

Although graphene has been widely used as a nano-filler to enhance the conductivity of porous materials, it is still an unsatisfactory requirement to prepare graphene-based sponge porous materials by simple and low-cost methods to enhance their mechanical properties and make them have good [...] Read more.

Although graphene has been widely used as a nano-filler to enhance the conductivity of porous materials, it is still an unsatisfactory requirement to prepare graphene-based sponge porous materials by simple and low-cost methods to enhance their mechanical properties and make them have good sensing and capacitive properties. Graphene platelets (GnPs) were prepared by the thermal expansion method. Graphene-based sponge porous materials were prepared by a simple method. A flexible sensor was formed and supercapacitors were assembled. Compared with other graphene-based composites, the graphene-based composite sponge has good electrical response under bending and torsion loading. Under 180° bending and torsion loading, the maximum resistance change rate can reach 13.9% and 52.5%, respectively. The linearity under tension is 0.01. The mechanical properties and capacitance properties of the sponge nanocomposites were optimized when the filler fraction was 1.43 wt.%. The tensile strength was 0.236 MPa and capacitance was 21.4 F/g. In cycles, the capacitance retention rate is 94.45%. The experimental results show that the graphene-based sponge porous material can be used as a multifunctional flexible sensor and supercapacitor, and it is a promising and multifunctional porous nanocomposite material. Full article

(This article belongs to the Special Issue Applications of Graphene-Based Materials in Sensors)

► Show Figures

Figure 1

13 pages, 6993 KiB

Open AccessArticle

A Graphene-Based Glycan Biosensor for Electrochemical Label-Free Detection of a Tumor-Associated Antibody

by Filip Kveton, Anna Blsakova, Lenka Lorencova, Monika Jerigova, Dusan Velic, Ola Blixt, Bo Jansson, Peter Kasak and Jan Tkac

Sensors 2019, 19(24), 5409; https://doi.org/10.3390/s19245409 - 9 Dec 2019

Cited by 17 | Viewed by 3285

Abstract

The study describes development of a glycan biosensor for detection of a tumor-associated antibody. The glycan biosensor is built on an electrochemically activated/oxidized graphene screen-printed electrode (GSPE). Oxygen functionalities were subsequently applied for covalent immobilization of human serum albumin (HSA) as a natural [...] Read more.

The study describes development of a glycan biosensor for detection of a tumor-associated antibody. The glycan biosensor is built on an electrochemically activated/oxidized graphene screen-printed electrode (GSPE). Oxygen functionalities were subsequently applied for covalent immobilization of human serum albumin (HSA) as a natural nanoscaffold for covalent immobilization of Thomsen-nouvelle (Tn) antigen (GalNAc-O-Ser/Thr) to be fully available for affinity interaction with its analyte—a tumor-associated antibody. The step by step building process of glycan biosensor development was comprehensively characterized using a battery of techniques (scanning electron microscopy, atomic force microscopy, contact angle measurements, secondary ion mass spectrometry, surface plasmon resonance, Raman and energy-dispersive X-ray spectroscopy). Results suggest that electrochemical oxidation of graphene SPE preferentially oxidizes only the surface of graphene flakes within the graphene SPE. Optimization studies revealed the following optimal parameters: activation potential of +1.5 V vs. Ag/AgCl/3 M KCl, activation time of 60 s and concentration of HSA of 0.1 g L⁻¹. Finally, the glycan biosensor was built up able to selectively and sensitively detect its analyte down to low aM concentration. The binding preference of the glycan biosensor was in an agreement with independent surface plasmon resonance analysis. Full article

(This article belongs to the Special Issue Applications of Graphene-Based Materials in Sensors)

► Show Figures

Figure 1

16 pages, 7112 KiB

Open AccessArticle

NO₂ and NH₃ Sensing Characteristics of Inkjet Printing Graphene Gas Sensors

by Caterina Travan and Alexander Bergmann

Sensors 2019, 19(15), 3379; https://doi.org/10.3390/s19153379 - 1 Aug 2019

Cited by 20 | Viewed by 4441

Abstract

Graphene is a good candidate for filling the market requirements for cheap, high sensitivity, robust towards contamination, low noise, and low power consumption gas sensors, thanks to its unique properties, i.e., large surface, high mobility, and long-term stability. Inkjet printing is a cheap [...] Read more.

Graphene is a good candidate for filling the market requirements for cheap, high sensitivity, robust towards contamination, low noise, and low power consumption gas sensors, thanks to its unique properties, i.e., large surface, high mobility, and long-term stability. Inkjet printing is a cheap additive manufacturing method allowing fast, relatively precise and contactless deposition of a wide range of materials; it can be considered therefore the ideal technique for fast deposition of graphene films on thin substrates. In this paper, the sensitivity of graphene-based chemiresistor gas sensors, fabricated through inkjet printing, is investigated using different concentrations of graphene in the inks. Samples have been produced and characterized in terms of response towards humidity, nitrogen dioxide, and ammonia. The presented results highlight the importance of tuning the layer thickness and achieving good film homogeneity in order to maximize the sensitivity of the sensor. Full article

(This article belongs to the Special Issue Applications of Graphene-Based Materials in Sensors)

► Show Figures

Figure 1

11 pages, 9789 KiB

Open AccessArticle

Stress-Insensitive Resonant Graphene Mass Sensing via Frequency Ratio

by Xing Xiao, Shang-Chun Fan, Cheng Li and Wei-Wei Xing

Sensors 2019, 19(13), 3027; https://doi.org/10.3390/s19133027 - 9 Jul 2019

Cited by 12 | Viewed by 3699

Abstract

Herein, a peripherally clamped stretched square monolayer graphene sheet with a side length of 10 nm was demonstrated as a resonator for atomic-scale mass sensing via molecular dynamics (MD) simulation. Then, a novel method of mass determination using the first three resonant modes [...] Read more.

Herein, a peripherally clamped stretched square monolayer graphene sheet with a side length of 10 nm was demonstrated as a resonator for atomic-scale mass sensing via molecular dynamics (MD) simulation. Then, a novel method of mass determination using the first three resonant modes (mode11, mode21 and mode22) was developed to avoid the disturbance of stress fluctuation in graphene. MD simulation results indicate that improving the prestress in stretched graphene increases the sensitivity significantly. Unfortunately, it is difficult to determine the mass accurately by the stress-reliant fundamental frequency shift. However, the absorbed mass in the middle of graphene sheets decreases the resonant frequency of mode11 dramatically while having negligible effect on that of mode21 and mode22, which implies that the latter two frequency modes are appropriate for compensating the stress-induced frequency shift of mode11. Hence, the absorbed mass, with a resolution of 3.3 × 10⁻²² g, is found using the frequency ratio of mode11 to mode21 or mode22, despite the unstable prestress ranging from 32 GPa to 47 GPa. This stress insensitivity contributes to the applicability of the graphene-based resonant mass sensor in real applications. Full article

(This article belongs to the Special Issue Applications of Graphene-Based Materials in Sensors)

► Show Figures

Figure 1

14 pages, 6525 KiB

Open AccessArticle

Near Room Temperature Light-Activated WS₂-Decorated rGO as NO₂ Gas Sensor

by Valentina Paolucci, Seyed Mahmoud Emamjomeh, Luca Ottaviano and Carlo Cantalini

Sensors 2019, 19(11), 2617; https://doi.org/10.3390/s19112617 - 9 Jun 2019

Cited by 39 | Viewed by 4641

Abstract

The NO₂ response in the range of 200 ppb to 1 ppm of a chemoresistive WS₂-decorated rGO sensor has been investigated at operating temperatures of 25 °C and 50 °C in dry and humid air (40% RH) under dark and [...] Read more.

The NO₂ response in the range of 200 ppb to 1 ppm of a chemoresistive WS₂-decorated rGO sensor has been investigated at operating temperatures of 25 °C and 50 °C in dry and humid air (40% RH) under dark and Purple Blue (PB) light conditions (λ = 430 nm). Few-layers WS₂, exfoliated by ball milling and sonication technique, with average dimensions of 200 nm, have been mixed with rGO flakes (average dimension 700 nm) to yield WS₂-decorated rGO, deposited on Si₃N₄ substrates, provided with platinum (30 μm gap distance) finger-type electrodes. TEM analysis showed the formation of homogeneous and well-dispersed WS₂ flakes distributed over a thin, continuous and uniform underlying layer of interconnected rGO flakes. XPS and STEM revealed a partial oxidation of WS₂ flakes leading to the formation of 18% amorphous WO₃ over the WS₂ flakes. PB-light irradiation and mild heating of the sensor at 50 °C substantially enhanced the baseline recovery yielding improved adsorption/desorption rates, with detection limit of 400 ppb NO₂ and reproducible gas responses. Cross sensitivity tests with humid air interfering vapor highlighted a negligible influence of water vapor on the NO₂ response. A charge carrier mechanism between WS₂ and rGO is proposed and discussed to explain the overall NO₂ and H₂O response of the WS₂–rGO hybrids. Full article

(This article belongs to the Special Issue Applications of Graphene-Based Materials in Sensors)

► Show Figures

Figure 1

Review

Jump to: Editorial, Research

30 pages, 711 KiB

Open AccessReview

Development of Graphene Quantum Dots-Based Optical Sensor for Toxic Metal Ion Detection

by Nur Ain Asyiqin Anas, Yap Wing Fen, Nur Alia Sheh Omar, Wan Mohd Ebtisyam Mustaqim Mohd Daniyal, Nur Syahira Md Ramdzan and Silvan Saleviter

Sensors 2019, 19(18), 3850; https://doi.org/10.3390/s19183850 - 6 Sep 2019

Cited by 80 | Viewed by 6447

Abstract

About 71% of the Earth’s surface is covered with water. Human beings, animals, and plants need water in order to survive. Therefore, it is one of the most important substances that exist on Earth. However, most of the water resources nowadays are insufficiently [...] Read more.

About 71% of the Earth’s surface is covered with water. Human beings, animals, and plants need water in order to survive. Therefore, it is one of the most important substances that exist on Earth. However, most of the water resources nowadays are insufficiently clean, since they are contaminated with toxic metal ions due to the improper disposal of pollutants into water through industrial and agricultural activities. These toxic metal ions need to be detected as fast as possible so that the situation will not become more critical and cause more harm in the future. Since then, numerous sensing methods have been proposed, including chemical and optical sensors that aim to detect these toxic metal ions. All of the researchers compete with each other to build sensors with the lowest limit of detection and high sensitivity and selectivity. Graphene quantum dots (GQDs) have emerged as a highly potential sensing material to incorporate with the developed sensors due to the advantages of GQDs. Several recent studies showed that GQDs, functionalized GQDs, and their composites were able to enhance the optical detection of metal ions. The aim of this paper is to review the existing, latest, and updated studies on optical sensing applications of GQDs-based materials toward toxic metal ions and future developments of an excellent GQDs-based SPR sensor as an alternative toxic metal ion sensor. Full article

(This article belongs to the Special Issue Applications of Graphene-Based Materials in Sensors)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Applications of Graphene-Based Materials in Sensors

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (8 papers)

Editorial

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI