Highly Selective Low-Temperature Acetone Sensor Based on Hierarchical 3-D TiO₂Nanoflowers

A Review of Biosensors for Non-Invasive Diabetes Monitoring and Screening in Human Exhaled Breath

“…Interestingly, the VOCs are associated with different human diseases. Exhaled breath acetone has been identified as a biomarker for diabetes [3], [5]- [7] because of its high positive correlation with blood glucose [8] (figure 2). Unfortunately, its concentration in human body is generally very low (0.1 ppm -0.8 ppm), while it might be high in the case of metabolism disorders, including diabetes mellitus (DM) (1.8 ppm -5.0 ppm) [7], [9]- [16].…”

“…Ideal breath acetone biosensors for diabetes are required to detect acetone down to sub-part per million (sub-ppm) level [5], [13]. In addition, it must be free or less affected by high relative humidity (RH) [32] as human exhale breath contains about 80% to 90% RH or even more [32].…”

“…Different other materials (other than SnO 2 , WO 3 and ZnO) have also been explored [5], [33], [35], [49], [52], [62]- [77]. Table 1 shows details about all the chemiresistive sensors for diabetes.…”

“…Most of their LOD covers diabetes range. However, few start from range of doubt [5], [35], [78]. Range of doubt means the range between normal and diabetes (which indicates those at risk).…”

Electronic nose for analysis of volatile organic compounds in air and exhaled breath.

“…Chemiresistors metal oxide composites [51][52][53][54][55][56][57][58][59], carbon nanotubes [60,61], semiconductors [62], polymer nanofibers [63,64], and nanoparticle-based materials [65] for detection of acetone as well as a plethora of other VOCs [66,67]. The chemical interaction between the sensing material and the analyte can be by covalent bonding, hydrogen bonding, or molecular recognition.…”