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 (<5 s).
In experiments, the response can reach 4.8 even at an extremely low
concentration of 10 ppb. Special attention is given to the interfacial
chemical reactions through 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.