Open AccessA New Strategy for Detecting Plant Hormone Ethylene Using Oxide Semiconductor Chemiresistors: Exceptional Gas Selectivity and Response Tailored by Nanoscale Cr 2 O 3 Catalytic Overlayer
Author(s) -
Jeong SeongYong,
Moon Young Kook,
Kim TaeHyung,
Park SeiWoong,
Kim Ki Beom,
Kang Yun Chan,
Lee JongHeun
Publication year - 2020
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201903093
Subject(s) - overlayer , ethylene , catalysis , selectivity , materials science , ethylene oxide , nanoscopic scale , oxide , semiconductor , nanotechnology , chemistry , chemical engineering , organic chemistry , polymer , optoelectronics , copolymer , engineering
A highly selective and sensitive detection of the plant hormone ethylene, particularly at low concentrations, is essential for controlling the growth, development, and senescence of plants, as well as for ripening of fruits. However, this remains challenging because of the non‐polarity and low reactivity of ethylene. Herein, a strategy for detecting ethylene at a sub‐ppm‐level is proposed by using oxide semiconductor chemiresistors with a nanoscale oxide catalytic overlayer. The SnO 2 sensor coated with the nanoscale catalytic Cr 2 O 3 overlayer exhibits rapid sensing kinetics, good stability, and an unprecedentedly high ethylene selectivity with exceptional gas response ( R a / R g − 1, where R a represents the resistance in air and R g represents the resistance in gas) of 16.8 at an ethylene concentration of 2.5 ppm at 350 °C. The sensing mechanism underlying the ultraselective and highly sensitive ethylene detection in the unique bilayer sensor is systematically investigated with regard to the location, configuration, and thickness of the catalytic Cr 2 O 3 overlayer. The mechanism involves the effective catalytic oxidation of interfering gases into less‐ or non‐reactive species, without limiting the analyte gas transport. The sensor exhibits a promising potential for achieving a precise quantitative assessment of the ripening of five different fruits.