We report here a prototype laboratory setup for detecting ethylene (C2H4) in ppm level employing a sensor made of multiwalled carbon nanotubes of 40 nm average tube diameter. The proposed reversible chemoresistive ethylene sensor is fabricated using Kapton as the substrate onto which carbon nanotubes are coated using thick film technology. IDT silver electrodes are printed using piezo head based ink-jet printing technology. The increases in electrical resistance of the sensor element are measured on exposure to ethylene for different ethylene concentrations using a potentiostat and data acquisition system. The increase in resistance of the calibrated sensor element on exposure to ethylene (analyte) is about 18.4% at room temperature for 50 ppm ethylene concentration. This change is reversible. Our sensor element exhibits a better performance than those reported earlier (1.8%) and it has got the rise and fall time of 10 s and 60 s, respectively. It could be used for testing the ripening of fruits.

Kathirvelan J

Department of Sensor and Biomedical Technology

School of Electronics Engineering

Vellore Campus

Vijayaraghavan R

Department of Chemistry

School of Advanced Sciences

Fulltext

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Development of Prototype Laboratory Setup for Selective Detection of Ethylene Based on Multiwalled Carbon Nanotubes

Journal of Sensors

We report the fabrication and testing of a prototype ethylene sensing device for use in fruit ripening applications. A sensor based on infrared (IR) thermal emission was developed and used to detect the ethylene level released during the fruit ripening process. An IR thermal source tuned to the 10.6 µm wavelength was linked to a high-sensitivity silicon temperature detector. When introduced into the wave path between the IR source and temperature detector, ethylene absorbs the 10.6 µm IR waves and decreases the surface temperature of the detector. The output is then converted to an electrical signal (in mV), which gives a direct measurement of the ethylene level. Using this sensor, ethylene concentration measured from a fruit sample continuously decreased from 59 to 5 ppm during the natural ripening process. The sensor exhibited a sensitivity of 3.3 ± 0.2% (change in detector output (mV)/ppm × 100) and could measure concentrations as low as 5 ppm with rise and recovery times of 1 and 3 s, respectively. The system demonstrated good reproducibility. Devices employing this sensor system may be used for fruit ripening applications on site and in the field and for screening artificially ripened fruits, therefore contributing to ensure food safety. © 2017 Elsevier B.V.

Infrared Physics & Technology

An infrared based sensor system for the detection of ethylene for the discrimination of fruit ripening

Purpose - The purpose of this paper was to develop a chemo-resistive sensor based on TiO2-WO3 composite material to detect and estimate ethylene released from the fruit ripening process to ensure food safety. Design/methodology/approach - The ethylene sensor has been fabricated using TiO2-WO3 composite material through the sol-gel method. Findings - The sensitivity of the sensor obtained using the pre-calibrated ethylene is found to be 46.2 per cent at 200 ppm ethylene concentration, and the proposed sensor could measure 8 ppm as the lowest concentration. Originality/value - The sensor was tested for continuous ethylene detection during natural ripening of fruits and hence is useful for ensuring food safety through discrimination of the type of fruit ripening. A TiO2-WO3 composite ethylene sensor is developed for the first time. © Emerald Publishing Limited.

Sensor Review

Ethylene detection using TiO2–WO3composite sensor for fruit ripening applications

Sensors and Actuators B: Chemical

Room temperature gas sensor based on tin dioxide-carbon nanotubes composite films

Multi-walled carbon nanotubes for volatile organic compound detection

Annals of Botany

Current methods for detecting ethylene in plants

Angewandte Chemie International Edition

Selective Detection of Ethylene Gas Using Carbon Nanotube-based Devices: Utility in Determination of Fruit Ripeness

Advanced Materials Research

CH4 and CO2 Detection by Using Carbon Nanotube-Based Sensors

Journal	Journal of Sensors
Publisher	Hindawi Limited
ISSN	1687-725X
Open Access	Yes