Sensing Applications Research Articles

Graphene-Based Fiber Materials for Gas Sensing Applications: State of the Art Review

The importance of gas sensors is apparent as the detection of gases and pollutants is crucial for environmental monitoring and human safety. Gas sensing devices also hold the potential for medical applications as health monitoring and disease diagnostic tools. Gas sensors fabricated from graphene-based fibers present a promising advancement in the field of sensing technology due to their enhanced sensitivity and selectivity. The diverse chemical and mechanical properties of graphene-based fibers—such as high surface area, flexibility, and structural stability—establish them as ideal gas-sensing materials. Most significantly, graphene fibers can be readily tuned to detect a wide range of gases, making them highly versatile in gas-sensing technologies. This review focuses on graphene-based composite fibers for gas sensors, with an emphasis on the preparation processes used to achieve these fibers and the gas sensing mechanisms involved in their sensors. Graphene fiber gas sensors are presented based on the chemical composition of their target gases, with detailed discussions on their sensitivity and performance. This review reveals that graphene-based fibers can be prepared through various methods and can be effectively integrated into gas-sensing devices for a diverse range of applications. By presenting an overview of developments in this field over the past decade, this review highlights the potential of graphene-based fiber sensors and their prospective integration into future technologies.

Precision Agriculture: UAV-Based Soil Mapping and Remote Sensing Applications

Using Unmanned Aerial Vehicle (UAV) equipped with remote sensing cameras that measure the electromagnetic spectrum of light reflected back from the ground below, this technology does soil mapping and field analysis. The way that different elements reflect different light wavelengths can be used to identify them. Reams of data on those wavelengths are gathered by multispectral image sensors, which power sophisticated AI software that can identify even the smallest variations in the elemental composition of soil. There are numerous positives to soil mapping, including helping farmers choose the best crops, applying the right fertilizers, and scheduling irrigation. Soil mapping also makes it easier to create plans for soil conservation and restoration that work. UAVs facilitate rapid deployment, enabling data collection near end-users, while delivering a more comprehensive and precise dataset compared to traditional camera-based methods. This study will provide effective technical support and decision-making assistance for future agricultural land planning.

Surface Water Monitoring Using GIS and Remote Sensing applications: Case study in Bau Sau, Cat Tien National Park

This study was conducted at Bau Sau, Cat Tien National Park, in Vietnam. Bau Sau is Vietnam's second wetland site out of a total of 9 Ramsar sites that have been recognized by the Ramsar Convention Secretariat in Vietnam. The extraction of surface water is carried out in three methods, including object-based classification and the calculation of NDWI and MNDWI indices. After calculating the overall accuracy of all three methods, the method with the highest percentage will be chosen for extracting the surface water boundary for the study area. With an overall accuracy of 90%, the NDWI index was used for extracting the water surface map in the period 2015–2024. The results also showed that the surface water area in Bau Sau was 42.15 hectares in 2015, 41.89 hectares in 2020, and 41.51 hectares in 2024. The fluctuation in the surface water area during 2015-2024 is clearly visible, showing a decrease of 0.64 hectares. The fluctuation is attributed to the vegetation communities, with the proliferation of Cyperus cephalotes being the most notable. Cat Tien National Park managers need to pay attention and take early measures in the near future to avoid impacting the habitat of some animal species in this area.

Utilizing the Achievements of Data Acquiring Solution and Cloud Service Platform for China-Africa Cooperation on Satellite Remote Sensing Application

Abstract. This study examines the collaborative approach in China-Africa satellite remote sensing initiatives based on solutions of satellite data acquiring, sharing and application experiences. It specifically addresses the data coverage requirements and current coverage scenarios of China's natural resources land satellites in Africa. By establishing the China-Africa Cooperation Centers on Satellite Remote Sensing Application, adopting a multi-level distributed technology center model, and implementing cross-continental remote sensing cloud services through an internet-based cloud platform, this initiative aims to enhance the direct utilization of satellite data in Africa. Furthermore, strategic satellite observation window designs tailored to seasonal changes have increased the frequency of valid coverage over the entire African continent to at least once a year. Such advancements pave the way for real-time monitoring applications, particularly in crucial areas such as sustainable development projects and disaster response efforts. Therefore, the study also provides some useful case studies that are anchored on the Sustainable Development Goals.

Trends of Remote Sensing applications for Amazon monitoring

Trends of Remote Sensing applications for Amazon monitoring

Modulation of the Chirality and Dynamics of Self-Assembled Nanocellulose-Chiral C-Dot Film for Chiral Sensing Applications.

The detection and sensing of chirality using chiral biomaterials are growing areas of research in advanced bioelectronics. As a result, chiral-controlled biomaterials are crucial for advancing current technologies in chiral sensing applications within biosystems. A chiral carbon dot (C-dot) modulated self-assembled emissive cellulose nanocrystal (CNC) film is developed where the chirality of the CNC film can be tempered between left-handed and right-handed chirality after being doped with chiral L/D-C-dots in CNCs (C-dot-CNC film), transferring the chirality from C-dots to CNCs. The interaction between C-dots, CNCs, and carrier dynamics is investigated using a variety of steady-state and time-resolved PL spectroscopy techniques. The chiral C-dot enhanced the protonic conductivity across the CNC via the formation of hydrogen bonds with its surface functional groups and water molecules. Further, the chiral CNC-C-dots photoelectrodes demonstrate an excellent ability to distinguish between left-handed and right-handed small molecules. These findings on the underlying mechanism of spin selectivity between chiral CNC-C-dot and chiral ligand hold promise for the development of efficient chiral-sensing electronic devices.

Theoretical Investigation of Rhodium-Decorated Gallium Nitride Nanotubes for Sulfur Hexafluoride Decomposition Products Sensing and Scavenging Applications.

Gas-insulated switchgear (GIS) plays an important role as a modern power distribution device in power plants and power stations, which is commonly filled with SF6 insulating gas. During the equipment operation, the inevitable partial discharge causes SF6 to be broken down into gas (SF4, SOF2, SO2, and H2S), which degrades the insulation performance of the GIS. This paper is devoted to the detection of partial discharge and the removal of SF4 and SOF2, which are not conducive to insulation, by exploring new gas-sensing materials for characteristic gas detection. Based on first-principles calculation, on the one hand, the most stable adsorption configurations of rhodium-decorated gallium nitride nanotubes (Rh-GaNNTs) and gas adsorption systems were obtained. On the other hand, the doping and adsorption mechanisms were analyzed by band structure, density of states, deformation charge density, and molecular orbital theory. Subsequently, the gas-sensitive performance of Rh-GaNNTs for these four impurity gases was evaluated by analyzing the sensing response and recovery time. The adsorption stability and recovery time of Rh-GaNNTs to these gases are ranked as SF4 > SOF2 > SO2 > H2S; the order of influence of gas adsorption on sensitivity response is H2S > SO2 > SF4 ≈ SOF2. Calculation results show the potential of Rh-doped surfaces as reusable H2S and SO2 sensors and suggest their use as gas scavengers to remove SF4 and SOF2, especially SOF2.

AI-Enhanced Remote Sensing Applications in Earth Science Processes for Enhancing Sanitation Workers’ Safety

AI-Enhanced Remote Sensing Applications in Earth Science Processes for Enhancing Sanitation Workers’ Safety

Structural and Optical Characteristic of Fe10+ Ion Implanted Nanostructured WO3 Film for Gas Sensing Application

Structural and Optical Characteristic of Fe10+ Ion Implanted Nanostructured WO3 Film for Gas Sensing Application

PPY: PVA Blend Enhanced with Metal Salt for Gas Sensing Applications

PPY: PVA Blend Enhanced with Metal Salt for Gas Sensing Applications

Strategic Design of Anion-Responsive Triarylboranes Exhibiting Colorimetric and Fluorometric Red-Shift for Sensing and Optoelectronic Applications.

Triarylboranes (TABs) have been employed as colorimetric and/or fluorometric anion sensors. The majority of TAB-based anion sensors exhibit blue-shift modes of absorption and photoluminescence (PL) or turn off of PL, attributed to the intrinsic electronic polarity of the trivalent boron unit in their molecular designs. In this Concept article, we introduce a novel approach to modulating the photophysical properties of TABs toward a red-shift mode by balancing the dual, opposing roles of the amine-bridged TAB (phenazaborine). This molecular design strategy enables significant changes in color and emission response to anions, shifting to the lower energy regime in solution. Additionally, this approach is applicable to the solid-state modulation of PL in films and organic light-emitting diodes (OLEDs).

Machine Learning and Remote Sensing Applications for Assessing Land Use and Land Cover Changes for Under-monitored Basin

Urban sprawling caused by industrial and economic growth has significantly affected land use and land cover (LULC). Using satellite imagery for real-time examination in Kuantan has become exceedingly expensive due to the scarcity and obsolescence of real-time LULC data. With the advent of remote sensing and geographical information systems, LULC change assessment is feasible. A quantitative assessment of image classification schemes (supervised classification using maximum likelihood and deep learning classification using random forest) was examined using 2022 Sentinel-2 satellite imagery to measure its performance. Kappa coefficient and overall accuracy were used to determine the classification accuracy. Then, 32 years of LULC changes in Kuantan were investigated using Landsat 5 TM, Landsat 8 OLI, and Sentinel-2 based on the best classifier. Random forest classification outperformed maximum likelihood classification with an overall accuracy of 85% compared to 92.8%. The findings also revealed that urbanisation is the main factor contributing to land changes in Kuantan, with a 32% increase in the build-up region and 32% in forest degradation. Despite the subtle and extremely dynamic connection between ecosystems, resources, and settlement, these LULC changes can be depicted using satellite imagery. With the precision of using a suitable classification scheme based on comprehensive, accurate and precise LULC maps can be generated, capturing the essence of spatial dynamics, especially in under-monitored basins. This study provides an overview of the current situation of LULC changes in Kuantan, along with the driving factors that can help the authorities promote sustainable development goals.

Correlation Between Structural, Electrical, and Optical Properties of ZnO:In for Ethanol Gas Sensing Application

Correlation Between Structural, Electrical, and Optical Properties of ZnO:In for Ethanol Gas Sensing Application

Study on the Electrochemiluminescence Emission Mechanism of HOF-14 and Its Multimode Sensing and Imaging Application.

A novel hydrogen-bonded organic framework (HOF-14) has attracted much attention due to its excellent biocompatibility and low toxicity, but its research in the electrochemiluminescence (ECL) field has not been reported. In this work, the annihilation-type and coreactant-type ECL emission mechanisms of HOF-14 were studied systematically for the first time. It was found that the ECL quantum efficiency of HOF-14/TEA coreactant system was the highest, which was 1.82 times that of Ru(bpy)32+/TEA. Further, the ECL emission intensity of HOF-14/TEA system could achieve colorimetric (CL) imaging of mobile phone. We also discovered that HOF-14 had superior photoelectrochemical (PEC) performance. Based on the above research results, a unique HOF-14-based multimode sensing and imaging platform was constructed. The antibiotic Enrofloxacin (ENR) was selected as the detection target, and the Cu-Zn bimetallic single-atom nanozyme (Cu-Zn/SAzyme) with excellent peroxidase (POD)-like activity was used to prepare quenching probes. When the target ENR was present, Cu-Zn/SAzyme quenching probes were introduced to the surface of HOF-14 by the dual-aptamer sandwich method. Cu-Zn/SAzyme could catalyze diaminobenzidine (DAB) to produce brown precipitations to quench the ECL, PEC, and CL signals of HOF-14, realizing multimode detection of ENR. This work not only discovered excellent ECL and PEC property of new HOF-14 material but also systematically studied the ECL emission mechanism of HOF-14, and proposed a novel multimode sensing and imaging platform, which greatly improved the detection accuracy of target and showed great contributions to the field of ECL analysis.

Infrared Photodetectors: Recent Advances and Challenges Toward Innovation for Image Sensing Applications

Infrared Photodetectors: Recent Advances and Challenges Toward Innovation for Image Sensing Applications

Sub-GHz Wrist-Worn Antennas for Wireless Sensing Applications: A Review

Sub-GHz Wrist-Worn Antennas for Wireless Sensing Applications: A Review

Green Synthesis of Carbon Nanodots (CNDs) Moderated by Flavonoid Extracts from Moringa oleifera Leaves and Co-Doped Sulfur/Nitrogen (NS - CNDs - Fla) and Their Potential for Heavy Metals Sensing Application.

Carbon nano dots (CNDs) has received a lot of attention in recent years due to their potential use in various kinds of applications. Many conventional chemical methods have been used to synthesis CNDs, but these processes have several drawbacks, such as hazardous by products, harsh chemicals, and high costs. To overcome these issues, green chemistry has an importance in the development of CNDs. Thus, it is essential to explore green synthesis approaches for production the CNDs. In this context, a novel precursor using flavonoid extraction from Moringa oleifera leaves is proposed. Moringa oleifera is the "magic tree" which contains many bioactive compounds such as flavonoids, especially in its leaves. Natural flavonoids and glycosides with specific components of structure can bind to metal ions. The content of bioactive compounds such as total flavonoids found in Moringa oleifera leaves is 172.10mg/g. In addition, carbon (47.34%), nitrogen (51.67%), and sulfur (0.99%) are also the main composition. Then, the carbon nanodots (CNDs) synthesized in this research were moderated by flavonoid extract from Moringa oleifera using the hydrothermal method. The technique is easy, ecologically friendly, and requires neither specialized device or reagents. In practice, the CNDs produced are almost circular, with an average diameter of 3.49nm. Furthermore, we enhanced synthesis CNDs - Fla with heteroatoms of nitrogen (N) and sulfur (S). They display a broad excitation-emission spectrum, excitation-dependent emission, and extraordinary fluorescence. Therefore, the synthesis of CNDs using flavonoids from Moringa oleifera as precursors would be a great potential candidate for the development of novel types of heavy metals sensing.

Smart Carbon Fiber-Reinforced Polymer Composites for Damage Sensing and On-Line Structural Health Monitoring Applications.

High electrical conductivity, along with high piezoresistive sensitivity and stretchability, are crucial for designing and developing nanocomposite strain sensors for damage sensing and on-line structural health monitoring of smart carbon fiber-reinforced polymer (CFRP) composites. In this study, the influence of the geometric features and loadings of carbon-based nanomaterials, including reduced graphene oxide (rGO) or carbon nanofibers (CNFs), on the tunable strain-sensing capabilities of epoxy-based nanocomposites was investigated. This work revealed distinct strain-sensing behavior and sensitivities (gauge factor, GF) depending on both factors. The highest GF values were attained with 0.13 wt.% of rGO at various strains. The stability and reproducibility of the most promising self-sensing nanocomposites were also evaluated through ten stretching/relaxing cycles, and a distinct behavior was observed. While the deformation of the conductive network formed by rGO proved to be predominantly elastic and reversible, nanocomposite sensors containing 0.714 wt.% of CNFs showed that new conductive pathways were established between neighboring CNFs. Based on the best results, formulations were selected for the manufacturing of pre-impregnated materials and related smart CFRP composites. Digital image correlation was synchronized with electrical resistance variation to study the strain-sensing capabilities of modified CFRP composites (at 90° orientation). Promising results were achieved through the incorporation of CNFs since they are able to form new conductive pathways and penetrate between micrometer-sized fibers.

Combined Confocal‐Atomic‐Force Microscope Setup for Quantum Sensing Applications with Sub‐diffractional Spatial Resolution

Quantum sensors find applications ranging from material science to biophysics. Nitrogen‐vacancy (NV) center in diamond has been successfully implemented for measuring various types of signals. Optical NV center readout, routinely used in confocal microscopes, allows achieving high spatial resolution down to the diffraction limit. This work describes in detail the combined confocal‐atomic‐force microscope (confocal‐AFM), which takes advantage of sharp AFM cantilevers, and shows its possible applications for nanoscale resolution. It demonstrates the sub‐diffractional localization of NV centers with platinum‐coated cantilevers and the ability to separately address optically unresolved sensors using cantilevers with ferromagnetic coating. The presented setup exhibits a lateral resolution of 13 nm, providing a tool for nanoscale quantum sensing.

Pure and Ce-Doped MnO2–ZnO Nanocomposites for Colossal Dielectric Energy Storage and Gas Sensing Applications

Pure and Ce-Doped MnO2–ZnO Nanocomposites for Colossal Dielectric Energy Storage and Gas Sensing Applications