We report herein a nanocomposite that has a continuous phase of amorphous calcium carbonate (ACC) filled with fluorescent carbon quantum dots (CDs) and undergoes phase transitions triggered by changes in moisture content in organic solvents. The phase transitions involve aggregation of the nanocomposite particles (in the order of 20 nm) and crystallization of the ACC phase, expelling the CDs from the composite and generating fluorescent signals at the same time. This can be triggered with a moisture content as low as 15 ppm, and the intensity of the fluorescent signal can be correlated quantitatively with a moisture content of up to 100%.
Bibliographical noteFunding Information:
The authors are thankful for nancial support for this work from the National Science Foundation of China (21672065 and 21636003), the Fundamental Research Funds for the Central Universities (22221818014), the 111 Project (B18022), the Shanghai Pujiang Program (16PJ1402500), the National Special Fund for State Key Laboratory of Bioreactor Engineering (2060204), and the Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM).
© 2019 The Royal Society of Chemistry.