Transilient Response to Acetone Gas Using the Interlocking p+n Field-Effect Transistor Circuit

• Published in: Sensors (Basel, Switzerland) Vol. 18; no. 6; p. 1914
• Main Authors: Zhou, Xinyuan, Wang, Jinxiao, Wang, Zhou, Bian, Yuzhi, Wang, Ying, Han, Ning, Chen, Yunfa
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12.06.2018; MDPI
• Subjects: Acetaldehyde; Acetone; Diabetes; Diabetes mellitus; Field effect transistors; field-effect transistor; Gas sensors; Locking; Low voltage; metal oxide semiconductor sensor; Metal oxide semiconductors; Mn-doped ZnO; Patients; Relative humidity; Semiconductor devices; Toluene; transilient response; Transistor circuits; Transistors; Zinc oxide; metal oxide semiconductor sensor; field-effect transistor; Mn-doped ZnO; diabetes; transilient response
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s18061914

Low concentration acetone gas detection is significantly important for diabetes diagnosis as 1.8⁻10 ppm of acetone exists in exhaled breath from diabetes patients. A new interlocking p+n field-effect transistor (FET) circuit has been proposed for Mn-doped ZnO nanoparticles (MZO) to detect the acetone gas at low concentration, especially close to 1.8 ppm. It is noteworthy that MZO in this interlocking amplification circuit shows a low voltage signal of <0.3 V to the acetone <2 ppm while it displays a transilient response with voltage signal >4.0 V to >2 ppm acetone. In other words, the response to acetone from 1 ppm to 2 ppm increases by ~1233%, which is competent to separate diabetic patients from healthy people. Moreover, the response to 2 ppm acetone is hardly influenced by high relative humidity of 85%. In the meanwhile, MZO in this interlocking circuit possesses a high acetone selectivity compared to formaldehyde, acetaldehyde, toluene and ethanol, suggesting a promising technology for the widespread qualitative screening of diabetes. Importantly, this interlocking circuit is also applicable to other types of metal oxide semiconductor gas sensors. The resistance jump of p- and n-FETs induced by the change of their gate voltages is deemed to make this interlocking circuit produce the transilient response.