The sensitivity enhancement of TiO₂-based VOCs sensor decorated by gold at room temperature

Detection of hazardous toxic gases for air pollution monitoring and medical diagnosis has attracted the attention of researchers in order to realize sufficiently sensitive gas sensors. In this paper, we fabricated and characterized a Titanium dioxide (TiO2)-based gas sensor enhanced using the gold nanoparticles. Thermal oxidation and sputter...

A Plant-inspired Light Transducer for High-performance Near-infrared Light Mediated Gas Sensing

Constructing near-infrared light (NIR) light-enhanced room temperature gas sensors is becoming more promising for practical application. In this study, learning from the structure and photosynthetic process of chlorophyll thylakoid membranes in plants, the first “Thylakoid membrane” structural formaldehyde (HCHO) sensor is constructed by...

Carbon-Iron Electron Transport Channels in Porphyrin–Graphene Complex for ppb-Level Room Temperature NO Gas Sensing

It is a great challenge to develop efficient room-temperature sensing materials and sensors for nitric oxide (NO) gas, which is a biomarker molecule used in the monitoring of inflammatory respiratory diseases. Herein, Hemin (Fe (III)-protoporphyrin IX) is introduced into the nitrogen-doped reduced graphene oxide (N-rGO) to obtain a novel...

Humidity sensor based on multi-layer graphene (MLG) integrated onto a micro-hotplate (MHP)

This work demonstrates a humidity sensor based on two multi-layered graphene (MLG) strips monolithically integrated onto a micro-hotplate (MHP). A transfer-free approach was adopted to release the graphene from the catalyst to reduce device variations and ensure scalability. The sensing performance of the device was tested by exposing the device...

Functionalisation of Multi-Layer Graphene-Based Gas Sensor by Au Nanoparticles

A novel gas sensor based on multi-layered graphene (MLG) functionalised with gold nanoparticles (Au-NPs) is presented. We demonstrate for the first time that: (1) the signal saturates during the analyte exposure, something which does not occur in the pristine material and in graphene-based gas sensors in general; (2) the sign of the device...

Effect of Humidity on Gas Sensing Performance of Carbon Nanotube Gas Sensors Operated at Room Temperature

Carbon nanotubes (CNTs) have shown promising results for gas sensing due to their high surface area. Since humidity has a great impact on the electrical conductivity of resistive CNT gas sensors, we have investigated the change of humidity on their sensing properties. In this study, we fabricated vertically aligned CNT-based gas sensors for the...

Analysis of a calibration method for non-stationary CVD multi-layered graphene-based gas sensors

Limitations such as lack of detected stationary signal and slow signal recovery after detection currently affect graphene-based chemi-sensors operating at room temperature. In this work, we model the behavior of a sensor in a test chamber having limited volume and simulating the environmental conditions. From this model, we mathematically derive...

Dynamics of interacting graphene membranes

Micro and nanomechanical sensors are indispensable in modern consumer electronics, automotive and medical industries. Gas pressure sensors are currently the most widespread membrane-based micromechanical sensors. By reducing their size, their unit costs and energy consumption drops, making them more attractive for integration in new applications...

Advances in the Electronics for Cyclic Voltammetry: The Case of Gas Detection by Using Microfabricated Electrodes

This paper presents an advanced voltammetric system to be used as electronic tongue for liquid and gas analysis. It has been designed to be more flexible and accurate with respect to other existing and similar systems. It features improved electronics and additional operative conditions. Among others these include the possibility to optically...

Gas Phase Sensing of Alcohols by Metal Organic Framework-Polymer Composite Materials

Affinity layers play a crucial role in chemical sensors for the selective and sensitive detection of analytes. Here, we report the use of composite affinity layers containing Metal Organic Frameworks (MOFs) in a polymeric matrix for sensing purposes. Nanoparticles of NH₂-MIL-53(Al) were dispersed in a Matrimid polymer matrix with...

Functionalizing a Tapered Microcavity as a Gas Cell for On-Chip Mid-Infrared Absorption Spectroscopy

Increasing demand for field instruments designed to measure gas composition has strongly promoted the development of robust, miniaturized and low-cost handheld absorption spectrometers in the mid-infrared. Efforts thus far have focused on miniaturizing individual components. However, the optical absorption path that the light beam travels...

Low Temperature CVD Grown Graphene for Highly Selective Gas Sensors Working under Ambient Conditions

In this paper we report on gas sensors based on graphene grown by Chemical Vapor Deposition at 850 °C. Mo was used as catalyst for graphene nucleation. Resistors were directly designed on pre-patterned Mo using the transfer-free process we recently developed, thus avoiding films damage during the transfer to the target substrate. Devices...

Electrosprayed Metal Oxide Semiconductor Films for Sensitive and Selective Detection of Hydrogen Sulfide

Semiconductor metal oxide films of copper-doped tin oxide (Cu-SnO2), tungsten oxide (WO3) and indium oxide (In2O3) were deposited on a platinum coated alumina substrate employing the electrostatic spray deposition technique (ESD). The morphology studied with scanning electron microscopy (SEM) and atomic force microscopy (AFM) shows porous...