Ultra-small TiO2 nanocubes with highly active (0 0 1) facet for acetone fast detection and diagnosis of diabetes

Early and painless detection of type-I diabetic patients by detecting acetone concentration in their exhaled breath would be a rapid and effective means. TiO 2 materials with exposed active (0   0   1) facet were synthesized mostly with HF as raw material, and the particle size was relatively large. In this work, (0   0   1) and (1   0   1) facets co-doped TiO 2 nanocubes with particle size < 50 nm were successfully prepared by a simple one-step hydrothermal process assisted by the ionic liquid ([Bmim][BF 4 ]) as the fluorine source and morphology modifier. Due to the exposure of the active (0   0   1) facets, the sensor exhibited good gas response to acetone gas at a low operating working temperature (OWT) of 170 °C with a detection limit as low as 30 ppb and a response time of only 2.2 s for 100 ppm acetone gas, and also relatively excellent selectivity, reproducibility, moisture resistance and long-term stability. It is worthy to point that, the changes of acetone concentration were compared in exhaled gas from healthy people and type-I diabetic patients, and the responses to exhaled gas of type-I diabetic patients were also tracked at different time in the same day. This provides significant convenience for early and painless diagnosis of type-I diabetic patients.