Ultrasensitive Acetone Gas Sensor Based on a K/Sn–Co3O4 Porous Microsphere for Noninvasive Diabetes Diagnosis

The detection of acetone in human exhaled breath is crucial for the noninvasive diagnosis of diabetes. However, the direct and reliable detection of acetone in exhaled breath with high humidity at the parts per billion level remains a great challenge. Here, an ultrasensitive acetone gas sensor based on a K/Sn-Co