Figure 6 Applications of UPy-CDs in information encryption and security.
Conclusions
In summary, a facile supramolecular strategy to prepare matrix-free RTP CDs materials has been reported, which relies on the post-modification of UPy recognition units to the surface of CDs. The strong hydrogen bonding induced by surface UPy groups not only stabilizes the singlet excited state, but also result in the efficient population of triplet state. As a result, the after-glow emission can be easily observed by the naked eye from UPy-CDs powder under ambient conditions, with a long emission lifetime of 33.6 ms. On account of these combined attributes, the potential application of UPy-CDs in information security was further explored. To our best knowledge, the matrix-free RTP has rarely reported for CDs and this work paves a new avenue for the rational design of CDs based RTP materials that are suitable for scalable production.
Experimental