Highly Sensitive Resistive Gas Sensor for Monitoring Ethyl Formate Emissions from Fish Meal

Abstract

Reliable and real-time monitoring of seafood spoilage has become an increasing concern in the field of food safety and human health. Ethyl formate released from seafood can characterise its freshness, but how to accurately detect ethyl formate is still a great challenge. In this study, the 3D ZnO sensing material with a honeycomb like structure was prepared using a one-step solvothermal reduction method in a specific triethylene glycol solution environment and high temperature for detecting ethyl formate gas in food. The material synthesis process and gas intake process present a simple and clear flowchart. The average diameter of the folded porous microspheres of the 3D ZnO sensing material was analyzed by SEM to be 0.67 μm. According to the sensing results, the gas sensor based on 3D ZnO has high sensitivity (69.68-100 ppm) at 280℃ and 43% RH, and good sensitivity (10.75-100 ppm) at 280℃ and 80% RH. It has an extremely low theoretical detection limit of 10 ppb at 43% RH, and exhibits excellent selectivity, repeatability, and long-term stability. The sensing mechanism is due to the gain or loss of electrons caused by the sensor surface reaction. In addition, the unique honeycomb like structure, abundant oxygen vacancies, and large surface area may be another factor contributing to its excellent formic acid ethyl ester gas sensing performance. This work highlights the potential of high sensitivity ethyl formate gas sensors to accurately evaluate seafood quality.

Keywords: Ethyl formate. Gas sensors. ZnO. Sensor performance. Volatile Organic Compounds.