Abstract
As a fruit ripening hormone, ethylene gas is effective at greater than 0.1 ppm. There are significant costs associated with ignoring the ethylene gas produced by (or surrounding) fruit at the various stages of postharvest. In this paper, a new approach for postharvest ethylene sensing is introduced, in which electrocatalytic oxidation of ethylene molecules on the sensor produces an amperometric signal. The electrochemical sensor developed by Fluid Analytics, ETH-1010, has been packaged into a complete field portable unit. It continuously samples and monitors the ethylene in air at a specified flow rate, commonly between 100 and 500 mL/min. The direct contact between the molecules in air and electrocatalytic surface renders this process more sensitive and responsive than conventional diffusion-type electrochemical cells. The detection threshold for our sensors has been better than 100 ppb, although a detection threshold of 10 ppb and better have also been developed and tested with this device. The overall system for this sensing approach is relatively simple and requires few components, thus providing a very cost effective gas monitoring system. This paper describes the method of detection of ethylene and applications of the current device.
