A chemiresistive MEMS acetone gas sensor based on p-Rh2O3 -n-WO3 heterostructure for diagnosing diabetes and monitoring diabetic states

Breath acetone is the biomarker of the diabetes as its level is higher in diabetes patients than that in healthy people and also higher in medically untreated type 2 diabetes patients than that in the controlled ones. Therefore, by analysing the concentrations of the acetone in the breaths, the diabetes can be diagnosed and the diabetic state of the patients can be monitored. Due to its merits of ultralow power consumption, miniaturization and good integration ability into the multifunction system, the MEMS-structure gas sensor is more closer to the practical application. Here, we have fabricated an ultrasensitive MEMS-structure acetone gas sensor based on p-Rh ₂O ₃-n-WO ₃-heterostructure, with the detection limit of 110 ppb, under the power consumption of 26.5 mW. The sensor also has good selectivity, response repeatability and long-term stability. The sensor can discriminate the simulated breaths of diabetes patients from those of healthy people. The sensor's capability to monitor the diabetic state of the patients was also confirmed by testing the simulated breaths of the diabetes patients. The ultrasensitivity of the sensor can be ascribed to the formation of the p-n heterojunction between p-type Rh ₂O ₃ and n-type WO ₃ and the catalytic capability of Rh ₂O ₃ towards acetone. The sensor has a great potential to be applied clinically in the diabetes diagnosis and the diabetic state monitoring.