Fluorescent pressure sensor based on TiO2/carbon quantum dots bifunctional nanocomposite film.

Fluorescent TiO₂/carbon quantum dots (CQDs) nanocomposites are prepared through incorporating CQDs into TiO₂ nanofilms, which are regarded as pressure sensitives to fabricate fluorescent pressure sensors for the first time. The TiO₂/CQDs sensors emit bright white fluorescence, and the fluorescence intensity of the TiO₂/N-doped CQDs (NCQD) sensor is much higher than the TiO₂/undoped CQDs (UCQD). The current response of the TiO₂/CQDs sensors have a good linear relationship with the applied pressure (R² > 0.96), while that of the pure TiO₂ sensor does not. Furthermore, the sensitivity of the TiO₂/NCQD sensor is 2.27 times larger than that of the TiO₂/UCQD sensor. In addition, the thickness of the nanocomposite film has a great influence on pressure sensing. The fluorescence and sensing performance of the fluorescent pressure sensors based on TiO₂/CQDs nanocomposite films are expected to be further simultaneously optimized by modulating CQDs for dynamically monitoring indoor security, such as recognizing the hit from the outdoor and simultaneously generating a self-warning signal of abnormal ultraviolet illumination from the surroundings. [ABSTRACT FROM AUTHOR]