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 (R-2 > 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.

Automated summary

Fluorescent TiO2/carbon quantum dots nanocomposites were prepared for the first time to fabricate pressure sensors. The NCQD sensor showed higher fluorescence intensity and a better linear relationship with applied pressure. Modulating CQDs can further optimize the sensing performance.