Ultrahigh Sensing Performance: Coresponse and Differentiation of Ethyl Acetate and Its Byproducts in Fe–Ce–O Interfacial Sensor

Accurately detecting low concentrations of ethyl acetate (EA) holds promise for the early screening of rectal and gastric cancer. The primary challenges lie in achieving a high response at parts per billion level concentration and ensuring high selectivity. This study focuses on designing Fe–Ce–O bimetallic oxides with doping and heterogeneous interfaces, which exhibit outstanding redox properties and highly enhanced ability of the adsorption and activation of both O2 and EA molecules. Benefiting from the violent reaction between EA and the adsorbed oxygen species, the sensor achieves an ultrahigh ethyl acetate sensing response of more than 500,000 at 200 ppm concentration, along with an ultrafast recovery rate (in situ DRIFTS during the sensing process. We propose for the first time that the produced intermediate byproducts (acetaldehyde, ethyl alcohol, acetic acid, and formic acid) coresponse on this sensor, contributing to its ultrahigh sensing response. Furthermore, both EA and the byproducts are effectively classified using linear discriminant analysis with 95% accuracy. This work is expected to elucidate the interfacial sensing mechanisms, particularly the contributions of derived byproducts to the sensor’s response, and to propose a novel idea for designing high-performance sensors.

精准检测低浓度乙酸乙酯（ethyl acetate, EA）有望用于直肠癌与胃癌的早期筛查。该领域的核心挑战在于实现十亿分之一（parts per billion, ppb）浓度级别下的高响应性能，并保障优异的选择性。本研究聚焦于设计具备掺杂结构与异质界面的铁铈双金属氧化物（Fe–Ce–O），该材料展现出优异的氧化还原特性，且对氧气（O₂）与乙酸乙酯分子的吸附及活化能力得到大幅提升。得益于乙酸乙酯与吸附氧物种间的剧烈反应，该传感器在200 ppm浓度下对乙酸乙酯的传感响应高达50万以上，同时具备超快速的恢复性能，相关传感过程通过原位漫反射红外傅里叶变换光谱（in situ DRIFTS）进行表征。本研究首次提出，反应生成的中间副产物（乙醛、乙醇、乙酸与甲酸）可在该传感器上产生协同响应，这是其超高传感响应的重要成因。此外，通过线性判别分析（linear discriminant analysis）可对乙酸乙酯与上述副产物实现有效分类，分类准确率达95%。本研究有望阐明界面传感机制，特别是衍生副产物对传感器响应的贡献，并为高性能气体传感器的设计提供全新思路。