Sensitive sensor for benzene detection in air: monitoring of benzene contamination in industry
Technology Status: TRL3 (tested in laboratory) PATENT GRANTED
Sectors of Application: Industry, health
Introduction
Benzene is one of the most harmful substances among volatile organic compounds (VOC). It is a flammable and toxic vapor recognized as a human carcinogen by the American Environmental Protection Agency or the European Commission. Prolonged exposure to benzene at relatively low concentrations for months or even years is known to generate severe hemotoxic problems such as aplastic anemia and pancytopenia and to produce non-lymphocytic leukemia. Exposure to benzene of workers and individuals is subject to strict regulations: individuals should not be exposed to concentrations of benzene of 0.1 ppm during 8 hours or 1 ppm during 15 minutes.
Therefore, there is a need to find new benzene gas detection devices that detect the presence of benzene gas even in the presence of other BTEX compounds (known aromatic VOCs) or other contaminants, providing a real time response, which present sensitivity and selectivity to benzene gas and allow its concentration to be quantified. It is further desirable to provide a device that is reversible, with low energy consumption for desorption and that can be manufactured with low cost consumables.
Description of solution
Researchers from ICIQ and URV prepared a new sensor based on multi wall carbon nanotubes (MWCNTs) treated with oxygen plasma and decorated with gold nanoparticles whose surface was functionalized by deep cavitands functionalized with quinoxaline walls. The mechanism of detection of the benzene occurs as depicted in the image below. The sensor is based on a selective molecular receptor of benzene self-assembled onto gold nanoparticles attached to carbon nanotubes forming a resistive electrode. The encapsulation of benzene provokes a change in the shape and electrical resistivity of the carbon nanotube, wich is measured by the electrode.
Advantages and unique selling points
- Highly sensitive and selective: The sensor has showed high response to benzene even in the presence of other similar aromatics with a theoretical limit of detection (LOD) of 600 ppt.
- Low power consumption: the sensing process is reversible at room temperature with the recovery of the resistance baseline upon air flushing, which is important for low power consumption. There is no need to use expensive consumables for each measurement.
- Adaptable: It is suitable for being integrated in hand-held portable analysers, wearable detectors and semi-passive radio frequency identification tags with sensing capabilities or in the nodes of wireless sensor networks.
- Large range of potential applications: The sensor can be used in environmental monitoring, workplace safety or medical devices, among others.
- Low cost commercialization: The simple experimental set-up ensures suitability for low cost commercialization and mass production.
Status of Technology
The sensor has been tested in the laboratory using a controlled environment.
Type of partnership sought
–Partner for joint development, scale-up and commercialization of the process is sought.
– Granted Patent rights available in Spain
IP Situation
A patent was granted in Spain
1-Title of the patent: Resistive sensor for detecting benzene gas and method for thr production thereof
-Application number: PCT/ES2015/070818
-Applicant: Fundació Institut Català d’Investigació Química (ICIQ) – Universitat Rovira i Virgili – Institució Catalana de Recerca i Estudis Avançats (ICREA)
-Inventors: Eduard Llobet (URV), Pierrick Clément (URV), Saša Korom, Pau Ballester
-Application date:
18 November 2014
References